Category: electromechanical technology

Problem Description

A Zoller smartCheck 450 fully automatic tool presetter (tool measuring machine) encountered issues where the C-axis failed to rotate and triggered program error alarms during measurement. The user confirmed that no software updates, circuit modifications, or maintenance operations had been performed recently, and the fault persisted after power cycling. Below is a comprehensive analysis of potential causes from aspects such as electrical control failures, encoder/motor issues, software configuration errors, sensor abnormalities, and limit/emergency stop signals, along with corresponding troubleshooting steps and solutions.

1. Electrical Control Cabinet Connection and ZUB Drive Inspection

Possible Causes

• The C-axis drive signal may not be transmitted properly, often due to loose wiring or power supply failures in the drive. The Zoller smartCheck series typically uses ZUB multi-axis motion control/drive modules to control the X/Z/C axes. Photos of the electrical control cabinet show a drive board labeled “zub” with thick cables MC1, MC2, etc. (presumably motor power and encoder/feedback lines). If these connections are loose, poorly contacted, or broken, the C-axis motor will not receive driving torque or feedback signals, preventing the C-axis from rotating.

Inspection Points

• Drive Connections: First, power off the machine and open the electrical control cabinet to inspect all connectors related to the C-axis on the ZUB drive. Pay special attention to whether the MC1 and MC2 cable interfaces are firmly plugged in, whether the plug locking mechanisms are in place, and whether there are signs of burn damage, discoloration, or breakage on the plugs and cables. If necessary, disconnect and reconnect them to ensure good contact. Also, check the normal connection of other drive interfaces (such as encoder interface X3, bus interface X8, etc.).
• Drive Indicators: Check the status indicators or digital displays (if any) on the ZUB drive module. Drives usually have power indicators and fault alarm lights. If there is a fault in the C-axis drive section, a red light may illuminate or an error code may be displayed. Record any abnormal indications for further consultation with the manufacturer’s technical documentation or support engineers.
• Drive Power Supply: Confirm that the drive power supply is normal. Measure the DC bus voltage or 24V control power supply of the drive (which should be supplied by the switching power supply in the control cabinet). Check whether there are fuses or electronic circuit breaker modules in the control cabinet that control the drive power output. For example, if electronic fuse modules such as Murr are installed in the cabinet, check whether the corresponding channel indicator lights are tripped due to overload (red light constantly on). If tripped, reset or replace the fuses according to the module instructions.
• Grounding and Shielding: Ensure that the grounding wires of the drive and motor are well connected. Loose grounding or shielding wires can introduce electrical noise and interfere with encoder signals, causing abnormal axis operation.

2. Zoller Control Module (Z1001/Z1004) Status

Possible Causes

• In addition to the main drive, there are control modules labeled Zoller Z1001 and Zoller Z1004 PZ in the electrical control cabinet. These modules may be responsible for signal distribution, I/O interfaces, or special functions (such as pneumatic control and sensor amplification). If these modules are related to C-axis control, their faults or poor contacts can also cause the C-axis to be uncontrollable.

Inspection Points

• Module Indicators: Observe the LED indicator states on the Z1001 and Z1004 modules. Normally, these modules should have a constant power indicator (green). In case of a fault, the modules may display a red fault light or flashing codes. Pay special attention to whether there are abnormal indications on modules related to C-axis control (such as Z1004 PZ, which may be related to the rotary axis or pneumatic braking).
• Wiring Terminals: Gently press the wiring terminals and plugs on each module with your hands to check for looseness. There are multiple rows of wiring on the Z1001/1004 modules. If some signal lines related to C-axis control (such as limit sensors, zero-position sensors, and braking solenoid valves) are loose, the C-axis action will be affected. Retighten all screw terminals and plugs to ensure a reliable connection.
• Module Functions: Refer to the module manuals for inspection if available. For example, the Z1004 PZ may be a “rotary table control module” (assuming PZ stands for “Prüf-Z Achse” or similar), which may have multiple adjustable potentiometers or fuses. If these fuse elements have tripped, reset or replace them as required. Similarly, the Z1001 may be the main control interface board, and its fault will affect the entire control logic. Check the appearance of these modules for burn damage or component脱落 (detachment). If module damage is suspected, contact Zoller after-sales service for further diagnosis.

3. C-Axis Motor and Encoder Faults

Possible Causes

• Mechanical or electrical faults may occur in the drive components of the C-axis itself, including motor damage, encoder signal loss, and axis brake not releasing. These will directly cause the axis to be unable to rotate and trigger errors during program execution.

Motor Faults

• If the C-axis motor has coil burnout, winding short-circuit, or bearing seizure, it will not rotate. In this case, the drive will usually report axis drive faults or short-circuit/overload alarms. Check whether the motor body is overheated, discolored, or has an abnormal odor. Manually rotate the spindle slightly (after ensuring safety and releasing the brake) to feel for excessive resistance or jamming. If the motor is severely damaged, it needs to be repaired or replaced.

Encoder Signal Interruption

• The C-axis requires an encoder to provide angle feedback. If the encoder is damaged or its signal line is interrupted, the drive will not be able to detect the position and will usually report a large position error or encoder fault alarm, causing the axis to be shut down for protection.
• Verification Method: Observe whether the C-axis angle reading on the Xpilot software interface changes. Slightly rotate the C-axis after power-off (after ensuring that the brake is released) and then power on to see if the software angle value changes; or manually read the value using the software without triggering the program. If the reading remains constant or changes abnormally, the encoder may have no feedback. In this case, check whether the encoder connection (usually through the MC2 cable) is loose. If necessary, use a multimeter to test the encoder power supply voltage or use an oscilloscope to check the encoder signal quality (this requires the intervention of professionals).

Brake Not Released

• Many measuring machines have electromagnetic or pneumatic brakes on the C-axis to lock the spindle and prevent rotation (to improve measurement accuracy). During rotation, the controller should unlock the brake. If the brake is stuck or does not receive the unlock command, the motor will be mechanically locked and unable to rotate.
• Troubleshooting Measures: Listen for the sound of the brake action when the C-axis attempts to rotate (electromagnetic brakes usually make a “click” sound, and pneumatic brakes make an airflow sound). Check whether the solenoid valve or relay that controls the brake works (the corresponding Z1001/1004 module may drive the brake signal). Also, confirm the air pressure: The nameplate of this model indicates that a 6-8 bar air source is required. If the air pressure is insufficient or the air circuit is blocked, the pneumatic brake cannot be released. Check whether the air pressure gauge reading is normal and whether there are air leaks or damages in the relevant air pipes. For electromagnetic brakes, measure whether there is approximately 24V voltage at its power supply terminals when the axis is enabled; if there is no voltage, it means that the control signal is not output, and the control circuit should be checked.

Mechanical Jamming

• After excluding the above electrical problems, it is not ruled out that the C-axis transmission mechanism is mechanically jammed (such as gear jamming or the clamping mechanism not being fully released). Under the premise of powering off and ensuring safety, manually rotate the C-axis to check its smoothness. If it is obviously unable to rotate and the influence of the brake is excluded, inspect the spindle transmission mechanism for foreign object blockage or damage.

4. Software Configuration and Program Logic Inspection

Possible Causes

• Software configuration errors or logical conflicts can also cause the C-axis to not rotate and program errors. For example, improper axis parameter configuration in the Xpilot (Pilot 3.0) software or problems in the program flow logic. Although the user stated that no software updates have been performed, the following situations still need to be considered:

Axis Parameter Configuration

• Enter the machine configuration menu in the Zoller Pilot software and check whether the C-axis is correctly identified and activated. For example, check parameters such as the travel range, zero-point position, and whether CNC control is enabled for the C-axis. Is it possible that the configuration file is damaged or parameters are lost, causing the C-axis to be uncontrolled (for example, abnormal internal controller axis card parameters)? If the configuration is found to be incorrect, restore the correct parameters (refer to the factory backup or contact the manufacturer for information). Pay special attention to the zero-point/reference point setting: Some devices require returning to zero at startup. If the software does not execute the return-to-zero operation and attempts to rotate, an error may be reported. Ensure that the reference points of each axis are initialized according to the correct procedure.

Program Logic Errors

• Review the measurement program (Sequence) that reported the error. Look for error prompts in the log at the bottom of the Xpilot interface. If the program reports an error at the step where the C-axis motion is called, it may be due to unsatisfied logical conditions. For example, the software may detect that a safety condition is not met (such as the tool not being clamped or exceeding the measurement range) and skip or abort the C-axis rotation. Verify whether the tool is correctly clamped and whether the tool parameters (such as tool length and diameter) in the software are within the allowable range to prevent the program from stopping due to the protection mechanism. You can also try to rotate the C-axis manually: Is there a manual JOG or specific function in the Pilot software to rotate the C-axis? If it cannot be rotated manually, it can basically be determined as a hardware/safety lock problem; if it can be rotated manually but not in the program, there may be a program logic error. In this case, consider re-recording the measurement sequence or checking the C-axis commands in the script.

Software Fault Reset

• If a software status abnormality is suspected (such as a cache error causing logical confusion), try to reinitialize the software. Close the Xpilot program and turn off the power supply of the industrial control computer. Wait a moment and then restart it to let the control system re-power on and initialize. If the software provides system diagnosis or reset options (such as the Pilot software may have diagnostic tools), run them to detect configuration errors. If necessary, consider backing up the data and then reinstalling or upgrading the software to a stable version to fix potential program bugs.

Internal Controller Parameters

• The motion control of some Zoller devices may be based on third-party CNC systems (for example, some cases mention that axis board parameter errors in the Syntec CNC system cause IO failures). Although the user has not changed the parameters, it is not ruled out that the controller parameters are disordered due to battery power failure or other reasons. If this situation is suspected, an engineer with permission should enter the controller debugging interface to verify the parameters of each axis, especially the drive configuration and feedback configuration of the C-axis.

5. Sensor Status and Safety Circuit Inspection

Possible Causes

• Abnormalities in safety protection and position sensors can also cause the C-axis to be locked and unable to rotate, commonly including false alarms from limit switches, unreset emergency stop circuits, and actions of other safety interlocks (such as protective doors and tool clamping sensors).

Limit Switches/Reference Point Sensors

• Confirm the status of the limit or zero-position sensors of the C-axis. Some tool presetters’ rotary tables may have zero-position sensors or limit switches with limited rotation ranges. If these sensors fail (for example, if the line of a normally closed switch is disconnected, the system will consider it to be in the over-limit position), the control system will prohibit the axis from continuing to move. Check the status of each input signal through the diagnosis interface of the Pilot software: Whether the C-axis limit is triggered (it should be in the normal untriggered state). If necessary, use a multimeter to measure the on-off state of the relevant sensors or lightly拨 (move) the sensor trigger plate to see if the status changes in the software to judge whether the sensor is stuck or the signal line is broken. If a sensor is found to be damaged or misaligned, it needs to be adjusted or replaced and then the alarm should be reset.

Emergency Stop Circuit

• Confirm that the emergency stop button is fully released and reset and that the safety relay in the emergency stop circuit has been pulled in. Zoller devices usually have a safety circuit to control the drive enable. If the emergency stop circuit is not closed, all axes will be stopped from driving. Check whether the indicator lights of the safety relay (such as Pilz or safety PLC modules) in the control cabinet are normal (usually green indicates closed and red indicates open). If the safety circuit is abnormal, check whether all emergency stop and safety door switches connected in series are closed. In addition, check whether the protective door/cover of the spindle box (if the device has a protective cover) is properly closed and whether the corresponding safety switch is closed.

Tool Clamping Sensor

• Ensure that the tool clamping status sensor is working properly. During measurement, C-axis rotation usually requires that the tool be properly clamped; otherwise, rotation may be prohibited for safety reasons. If the clamping sensor fails and falsely reports that the tool is not clamped, the software may report an error and abort the C-axis motion. Manually operate the clamping/unclamping and see if the software status indication changes accordingly. If the sensor or its connection is poor, repair it so that the software can detect the tool clamping signal and then reattempt the measurement program.

Other Related Sensors

• If the device has temperature, air pressure, and other monitoring functions, also confirm that there are no alarms (low air pressure may have been checked in the brake section above). In short, exclude any sensor signals that cause the control system to enter the protection mode.

6. Recommended Troubleshooting Steps and Recovery Measures

For the above possible causes, the following systematic diagnostic steps are recommended to eliminate faults one by one and attempt to restore the C-axis function:

Record Error Information

• When the fault occurs, record the content of the error dialog box or error code popped up on the Pilot software interface and the fault indications displayed on the drive/module in the control cabinet. This helps with targeted troubleshooting (for example, whether it prompts a drive fault, overtravel, or no reference point).

Preliminary Reset Attempt

• Press the reset/restore button of the machine (if any) or execute the reset command in the software. Ensure that the emergency stop button is released, and then clear the alarm in the Pilot software. Try to return to zero for each axis (especially the C-axis) and see if it can be completed. If the function is temporarily restored but the fault recurs, continue with the following steps.

Check Safety Status

• Ensure that all safety conditions are met: the emergency stop is not pressed, the protective door is closed, the air pressure is normal (indicated within the specified range), and the tool is correctly clamped. If any of these conditions are not met, resolve them first (such as releasing the emergency stop and establishing the air source) and then test again.

Power-Off Wiring Inspection

• Turn off the main power supply of the device and ensure power lockout. Open the electrical control cabinet and focus on checking the wiring and components related to the C-axis:
• Grip and gently shake the MC1 and MC2 cable connectors on the ZUB drive to confirm that they are not loose. Remove them, check that the pins are not burned or deformed, and then plug them back in firmly.
• Check whether all plugs and terminals on the Z1001 and Z1004 modules are plugged in tightly, especially the lines marked with the C-axis or spindle braking/sensing. If necessary, re-plug or tighten the screws.
• Check the power modules, fuses, and relays in the control cabinet: whether the 24V switching power supply output is normal (measure with a multimeter, which should be around 24V); whether the corresponding channel of the electronic fuse module has no red alarm; whether the safety relay indication is normal.
• Quickly visually inspect all wiring for脱落 (detachment) or broken strands, especially the cables in the drag chain of moving parts (such as the C-axis motor cable) for wear and breakage.

Power Supply and Drive Self-Check

• Before powering on, manually rotate down the emergency stop/enable switches of devices such as the ZUB drive (if any). After powering on, observe:
• Whether the power-on indicators on the drive are normally lit and whether a fault is reported immediately (if a red light illuminates immediately, it may indicate a hardware fault).
• Whether all module indicators are normal (no red lights).
• Whether no new alarms sound. Then, release the emergency stop/enable of the drive and observe the changes in the drive status lights: if everything is normal, it should enter the standby state.

Test Single-Axis Motion

• Under the premise of ensuring the safety of the X and Z axes, try to manually operate the C-axis. If the Pilot software provides a JOG or jogging function, give a low-speed rotation command to the C-axis:
• Normal Motion: If the C-axis can rotate at this time, it indicates that the basic drive hardware is fine, and the problem may lie in the program logic or the previously loose connection has been repaired. You can further test it multiple times to confirm its stability and then run the automatic measurement program.
• Unable to Move/Report Error: If there is still no response to the manual command and an error is reported, the problem still exists. Check the content of the new error report and focus on whether it prompts a drive fault or a safety interlock. If a drive fault is reported, go to Step 7; if it prompts safety or not ready, go back to Step 3 and check the sections that have not been completely eliminated.

In-Depth Hardware Diagnosis

• Use tools to further check the motor and encoder:
• Measure Motor Windings: After power-off, use a multimeter on the ohmmeter range to measure whether the resistances of the three-phase windings of the C-axis motor are balanced and not open-circuit, and whether the insulation to the ground is good. If abnormal (such as open-circuit or short-circuit to the ground), the motor is damaged and needs to be replaced.
• Check Encoder Feedback: If conditions permit, use an oscilloscope or encoder tester to check the signal quality of the C-axis encoder. If this is not possible, read whether the encoder count changes in the drive diagnosis interface. Any abnormal encoder feedback requires replacing the encoder or repairing the connection fault.
• Check Brake Control: If it is an electromagnetic brake, measure the voltage at both ends of the brake coil with a multimeter on the DC range when the C-axis is enabled: there should be approximately 24V when released and 0V when powered on but not enabled or when the emergency stop is pressed. If it is always 0V, it means that the control signal is not output (the problem is in the control circuit); if there is 24V but the axis is still locked, it means that the brake is mechanically stuck or not actually released (the problem is in the actuator), and the brake needs to be repaired or replaced. If it is a pneumatic brake, observe the action of the air valve and the change in air pressure before and after enabling the axis: if there is no action, measure the coil of its solenoid valve; if there is action but the pressure is insufficient, check the air circuit.

Introduction

Edwards, a global leader in vacuum technology, offers the EPX series vacuum pumps, renowned for their innovative design and exceptional performance. The EPX series is a high-vacuum primary pump that integrates regenerative and Holweck stage mechanisms, enabling efficient pumping from atmospheric pressure to ultimate vacuums as low as 1 x 10^-4 mbar or 1 x 10^-5 mbar, depending on the model. This design eliminates the need for additional turbomolecular pumps in many applications, simplifying system setups.

Widely used in industries such as semiconductor manufacturing, vacuum coating, analytical instrumentation, pharmaceuticals, and optoelectronics, the EPX series excels in high-vacuum, high-cleanliness, and high-reliability applications. This guide provides a comprehensive overview of the EPX series’ performance features, applications, operational procedures, usage details, and troubleshooting methods to assist users in maximizing the pump’s potential.

1. Performance Features

The EPX series vacuum pumps are engineered for superior performance in high-vacuum environments. Below are the key technical specifications:

Parameter	EPX180LE	EPX180NE	EPX500LE	EPX500NE
Peak Pumping Speed (m³/h)	175	175	500	500
Ultimate Vacuum (mbar)	<1 x 10^-4	<1 x 10^-4	<1 x 10^-5	<1 x 10^-5
Max Exhaust Pressure (bar)	0.2	0.2	0	0
Nitrogen Consumption (slm)	0	25	0	25
Cooling Water Consumption (l/h)	120	120	120	120
Supply Voltage (V)	200/208/400	200/208/400	200/208/400	200/208/400
Power at Ultimate (kW)	1.4	1.6	1.4	1.6
Maximum Power (kW)	3.0	3.0	3.0	3.0
Weight (kg)	45	47	46	48
Inlet/Outlet Connection	ISO63/NW25	ISO63/NW25	ISO160/NW25	ISO160/NW25
Noise (dB(A))	<56	<56	<56	<56
Vibration (mm/s, rms)	<1.3	<1.3	<1.3	<1.3

• Pumping Speed and Vacuum: The EPX180 delivers a pumping speed of 175 m³/h, while the EPX500 achieves 500 m³/h. All models reach <1 x 10^-4 mbar, with the EPX500 capable of 1 x 10^-5 mbar due to an additional helical rotor stage.
• Cooling System: Water cooling ensures a low environmental heat load, ideal for cleanroom settings.
• Cleanliness: The oil- and grease-free mechanism prevents contamination, suitable for high-purity processes.
• Nitrogen Purge: N variants (EPX180NE and EPX500NE) include a nitrogen purge facility for handling vapors and low-level corrosive gases and particulates.
• Compact Design: Weighing approximately 45-48 kg, the EPX is smaller than equivalent turbomolecular pump and primary pump combinations.
• Low Noise and Vibration: Noise levels below 56 dB(A) and inlet flange vibration under 1.3 mm/s ensure suitability for quiet environments.
• Power Efficiency: Supports 200/208/400 V three-phase power, with power consumption of 1.4-1.6 kW at ultimate vacuum and a maximum of 3.0 kW.

These features position the EPX series as a high-performance solution for demanding vacuum applications.

2. Applications

The EPX series vacuum pumps are designed for a variety of high-demand applications, including:

• High-Vacuum Processes: Ideal for applications requiring higher vacuum levels than typical primary pumps, such as semiconductor load locks, vacuum coating, and analytical instruments, where it can replace turbomolecular and primary pump combinations, reducing system complexity and cost.
• Frequent Pressure Cycling: Suitable for processes that cycle frequently between atmospheric and low pressures, such as load locks and rapid-cycle coating systems.
• High-Cleanliness Requirements: The oil-free design makes it perfect for pharmaceuticals, electronics, and optoelectronics, ensuring contamination-free systems.
• Corrosive Gas Handling: The nitrogen purge facility in N variants enables handling of vapors and low-level corrosive gases, suitable for light-duty corrosive processes.

The EPX series’ versatility and efficiency make it a preferred choice in semiconductor, scientific research, and industrial production settings.

3. Operational Procedures

Proper operation of the EPX series vacuum pump is critical to ensuring performance and safety. Below are the detailed steps for operation:

3.1 Preparation and Installation

• Installation Location: Install the pump in the vacuum system before connecting to the electrical supply to prevent accidental operation during setup, which could cause injury or equipment damage.
• Inlet Protection: Do not remove the inlet screen or operate the pump with the inlet exposed. If hazardous substances are involved, isolate the pump from the atmosphere and process system.
• Piping Connections: Connect the pump inlet to the process system using flexible connections to minimize vibration and stress. Use short pipes with an inner diameter no smaller than the pump inlet. Remove the inlet flange protective cap before installation and use an Edwards centering O-ring and claw clamps to seal the connection.

3.2 Connections

• Cooling Water: Connect the cooling water supply and return lines via customer-specified water connectors (refer to Figure 2, items 4 and 9). Ensure cooling water meets environmental conditions (humidity and temperature, refer to Table 5).
• Power Supply: Connect the electrical supply through a suitable fuse/isolator, ensuring proper grounding via the protective earth stud (Figure 2, item 3) in compliance with local electrical codes.
• Control Interface: Connect external control equipment via the Tool Interface Module (TIM) or End User Controller (EUC). The EPX L, N, and NE series use the EUC for local and network control, while the EPX E series supports manual operation via EUC or PDT.

3.3 Starting the Pump

• Use the run button on the EUC (Figure 7, item 1) to start the pump. The run LED (green) illuminates when the pump is operating normally.
• For EPX N series pumps, supply nitrogen purge gas through a 1/4-inch compression fitting labeled “N2 Inlet” using 1/4-inch OD tubing, ensuring stable flow (refer to Table 10).

3.4 Monitoring and Control

• Status Monitoring: Monitor pump status via front panel LEDs (refer to Table 1 and Figure 4):
  • Power LED (Green): Indicates main power supply is active.
  • Run LED (Green): Steady when running, flashing in idle mode.
  • Warning LED (Amber, EPX N only): Indicates low nitrogen flow.
  • Alarm LED (Red): Indicates shutdown due to a fault.
• Control Options: Use the EUC or PDT menus (Normal, Status, Control, Setup) to check status, adjust controls, and configure parameters. The EUC display provides two-line, 16-character pump status information.

3.5 Stopping the Pump

• Use the stop button on the EUC (Figure 7, item 10) to stop the pump.
• In emergencies, connect to an emergency stop circuit to disconnect power immediately, requiring a separate start or reset action.

Precautions

• Ensure proper grounding to prevent electrical hazards.
• Verify cooling water supply meets requirements to avoid overheating.
• For EPX N series, regularly confirm the nitrogen purge system is functioning correctly.

4. Usage Details

The EPX series vacuum pumps offer detailed operational features covering their operating range, variant functionalities, and protective mechanisms:

• Operating Range: The pumps operate from atmospheric pressure to ultimate vacuum without lubricating or sealing fluids in the pumping chamber, ensuring a clean system with no oil back-migration.
• Variants and Applications:
  • EPX L: Designed for clean tasks (e.g., load locks), supports local and network control via EUC.
  • EPX N: Equipped with a gas module for nitrogen purging, suitable for light-duty applications with diluted process gases.
  • EPX NE: Light-duty application pump with network and local control.
  • EPX E: Supports manual operation via EUC or PDT, ideal for network-controlled setups.
• Capacity and Configuration: Available in 180 m³/h (EPX180LE/NE) and 500 m³/h (EPX500LE/NE) capacities, with voltage options of 200/208 V or 400 V, and water connector options of 1/4, 3/8, or 9/16-inch BSP or no quick connects.
• Cooling System: Integrated water cooling circuit suits cleanroom environments, avoiding the drawbacks of fan cooling.
• Performance Optimization: The EPX Twin offers enhanced performance between 1 bar and 0.2 mbar, ideal for load locks and rapid cycling applications.
• Protective Mechanisms: Equipped with sensors like thermal cut-off switches to detect overheating and trigger automatic shutdowns. The EPX N series includes a nitrogen purge flow switch (set to 12 slm) to monitor flow.

5. Troubleshooting

Below are common issues with the EPX series vacuum pumps and their solutions:

Issue	Possible Cause	Solution
Pump Shutdown (Alarm LED On)	Overheating, drive fault	Cool the pump for at least 20 minutes, check cooling water supply (Section 2.4), restart.
Low Nitrogen Flow (Warning LED On)	Insufficient nitrogen supply	Verify nitrogen flow to the gas module; if persistent, contact Edwards service center.
Noise on Restart	Rapid reapplication of run signal	Allow the pump to fully stop before reapplying the run signal; noise is harmless.
Connection Issues	Incorrect control equipment connections	Verify interface connections (Section 3.11); if persistent, contact Edwards service center.

Safety and Maintenance

• Electrical Safety: Do not operate without proper grounding or correct electrical connections. The pump contains no user-serviceable parts; maintenance must be performed by Edwards professionals, with power disconnected for at least 4 minutes before removing covers.
• Pump Seizure: If the pump seizes, wear gloves, eye protection, and a face mask due to potential aluminum sulfate dust and sulfurous odors.
• Service Support: Contact Edwards service centers for repairs, spares, or accessories, providing model, serial number, and part details. Returns require a completed HS2 contamination form.

6. Conclusion

The Edwards EPX series vacuum pumps offer outstanding performance, versatility, and reliability for high-vacuum applications. Their oil-free design, high pumping speeds, and nitrogen purge capabilities make them ideal for semiconductor, pharmaceutical, and research industries. By following proper operational procedures, regular monitoring, and timely maintenance.

The rolling of tea leaves is a critical process in tea production. Its main goal is to twist the leaves into tight strips, rupture some of the leaf cells to promote the release of tea juice, and enhance the aroma and liquor of the tea. The tea rolling machine, as the key mechanical equipment for this task, has gradually replaced traditional manual rolling and is now widely used in the production of black, green, oolong, and other types of tea.

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1. Working Principle of the Tea Rolling Machine

The rolling machine operates by applying pressure between a top press cover and a rotating bottom disc, sandwiching the tea leaves. Through the combined motion of pressing and rotation, the leaves are subjected to extrusion, friction, and kneading forces, causing them to bend, twist, and partially rupture. This helps to form the desired strip shape and allows the internal tea juice to be released.

The main forces at work during rolling include:

• Shear Force: Facilitates shaping by shearing the leaves between two surfaces;
• Frictional Force: Generated as the leaves tumble between the disc and the cover, enhancing curl formation;
• Vertical Pressure: Continuously applied by the top cover to control the rolling intensity and leaf breakage rate.

The rolling process typically follows a sequence of “light pressure – medium pressure – heavy pressure – decompression” to ensure optimal shaping and internal quality.

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2. Key Structural Components

Tea rolling machines are robustly built and functionally arranged, typically consisting of the following parts:

1. Main Frame and Base Support
   Made of cast iron or steel, often tripod-style for excellent stability and vibration resistance.
2. Rolling Disc (Rotating Plate)
   Located at the base, made from stainless steel or cast aluminum, featuring spiral guide ribs to move the tea in a circular path. The surface is polished for easy cleaning.
3. Rolling Drum (Barrel)
   A cylindrical chamber fixed above the rotating disc where tea leaves are placed. Smooth and seamless inside for even rolling.
4. Pressing Cover Mechanism
   Positioned above the barrel, adjustable manually or electrically. The inner surface is curved or grooved to apply even downward pressure. A spring mechanism provides buffering.
5. Motor and Gearbox Drive
   Drives the rotating disc via belts or gears. Speed is typically reduced to 30–60 rpm for controlled operation.
6. Control Panel
   May include timers, press height adjustment knobs, power switches, and emergency stops.
7. Discharge Port
   Once rolling is complete, tea is discharged by lifting the cover or opening a side outlet. Some models have scraper mechanisms for efficient leaf removal.

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3. Operational Workflow

1. Leaf Loading

Processed (withered or de-enzymed) leaves are evenly spread into the barrel. No pressure is applied at this stage.

2. Initial Pressing

The press cover is gently lowered to just contact the leaves, stabilizing their position and forming the initial shape.

3. Rolling Phase

The motor activates the rotating disc. Under spiral guidance, the leaves tumble while being pressed by the top cover. This produces combined shearing and extrusion forces. Duration is 3–10 minutes depending on the tea type and batch size.

Rolling can be broken down into:

• Light rolling (low pressure, low speed)
• Medium rolling (increased pressure, steady speed)
• Heavy rolling (max pressure, fixed speed)
• Final shaping (reduced pressure, slow speed)

4. Discharging

The motor stops, the press cover is lifted or the outlet opened, and the rolled leaves are released.

5. Cleaning and Reset

Residual tea is cleaned off the disc and barrel to prepare for the next batch.

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4. Technical Specifications

Item	Typical Range	Description
Motor Power	1.1–3 kW	Depends on size and capacity
Rolling Disc Diameter	500–1200 mm	Larger size accommodates higher loads
Rotation Speed	30–60 rpm	Adjustable per tea type
Pressing Stroke	100–180 mm	Defines maximum compression depth
Rolling Time	2–15 minutes	Varies by tea type
Batch Capacity	10–100 kg per batch	Based on machine model
Pressing Mechanism	Manual / Electric / Pneumatic	Varies in precision and efficiency

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5. Control Logic Overview

Modern machines include integrated control features such as:

• Time Setting: Allows rolling duration to be preset;
• Press Cover Control: Motorized or electric actuator to fine-tune press height and pressure;
• Speed Regulation: When equipped with an inverter, stepless speed control is achievable;
• Emergency Stop: Ensures safe halt during abnormal operation;
• Directional Control: Enables clockwise and counterclockwise rotation alternation for uniform rolling.

These systems promote repeatable, standardized rolling results and reduce operator dependency.

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6. Structural Advantages and Craft Adaptability

1. Durable, Low-Wear Construction: Cast frame design minimizes vibration and extends service life;
2. Adjustable Pressure Cover: Adapts to different moisture levels and leaf volumes;
3. Spiral Ribbed Disc: Ensures continuous tumbling and even pressure distribution;
4. Easy Maintenance: Smooth surfaces reduce cleaning time and prevent residue build-up;
5. Automation-Friendly: Compatible with external control systems or PLC upgrades.

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7. Process Optimization Through Variable Speed Control

In modern tea production, varying tea varieties demand different rolling speeds and pressures. Equipping the machine with a variable frequency drive (VFD) allows flexible speed regulation to match these needs.

By adjusting the disc speed based on tea type (e.g., low speed for green tea, medium for black tea), the shaping and juice extraction can be precisely controlled. Multi-stage speed profiles—such as low for initial shaping, medium for heavy rolling, and low again for final adjustment—are easily managed by inverter systems, ensuring quality and efficiency.

A high-performance inverter like the Longi 900 series offers precise speed control, strong torque at low speeds, smooth acceleration, and good compatibility with industrial tea machinery. This enhances the consistency of rolling results while optimizing energy use and equipment protection.

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8. Conclusion

The tea rolling machine is central to the quality of processed tea. Its structural design, technical parameters, and control mechanisms must harmonize with tea characteristics to ensure optimal results.

As electrical and automation technology evolves, upgrading rolling machines with intelligent control and variable speed capability is becoming a standard in tea factory modernization. These advances preserve traditional craftsmanship while enhancing efficiency, consistency, and adaptability in production.

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1. Overview of the Process

The automatic chili pepper cooking production line consists of six main steps:

1. Raw Material Transport and Cleaning
   • Conveyor/Screw Lifter: Transports fresh chili peppers to the cleaning section.
   • Bubble Washing Machine: Uses water flow and bubbles to remove dirt, pesticides, and residues from the peppers.
2. Preprocessing: Sorting and Cutting
   • Sorting and Grading: Manual or vibrating conveyors automatically sort out defective peppers.
   • Cutting Equipment: Cuts peppers into segments or small pieces, ensuring uniform size for cooking and grinding.
3. Cooking for Flavor Extraction
   • Continuous Cooking Machine: Uses steam or electric heating to cook the peppers at 70°C to 90°C for 30 to 90 minutes, extracting flavor and heat while softening the peppers.
4. De-watering and Separation
   • Vibration Dewatering Machine: Removes excess water from the cooked peppers, making them easier to grind.
5. Flavoring and Grinding
   • Chili Paste Machine: Adds seasonings such as salt, sugar, garlic, and oil, then grinds the mixture into chili paste.
6. Packaging and Sterilization
   • Filling Machine → Sterilization Cooker: Quickly fills containers, seals, and sterilizes the chili paste to ensure freshness and shelf-life.
7. Storage
   • The finished products are stored in a cold storage or shipped for distribution.

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2. Equipment and Process Design Logic

The equipment configuration and sequence design are tailored to meet process requirements, enhancing automation and efficiency.

Stage	Key Equipment	Function
Transport & Cleaning	Screw Lifter → Bubble Washing Machine	Ensures uniform raw material size and cleanliness
Cutting	Sorting Table → Cutting Machine	Ensures uniform size for efficient cooking and grinding
Cooking → De-watering	Continuous Cooking Machine → Vibration Dewatering Machine	Evenly softens and separates water for easier processing
Flavoring & Grinding	Chili Paste Machine	Uniform mixing and grinding for consistent texture
Packaging & Sterilization	Filling Machine → Sterilization Cooker	Quick filling and sterilization to preserve quality

• Conveying and Cleaning: The screw lifter evenly transports peppers to the washing station, where bubbles and spray jets ensure thorough cleaning.
• Cutting: The cutting machine ensures uniform sizes, which is critical for consistent cooking and grinding results.
• Cooking: The peppers are evenly cooked using steam or electric heating, with mechanisms in place to ensure uniform heat distribution.
• De-watering: The vibration dewatering machine removes excess water, reducing processing load for the next stages.
• Flavoring & Grinding: The chili paste machine grinds the chili, creating uniform products with controlled spice levels.
• Packaging: The filling machine ensures consistent product weight, while the sterilization process ensures food safety.

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3. Automation Logic and Control Principles

The core of the automation system includes PLC + HMI + Frequency Inverter + Temperature Control System, working together to ensure seamless operation.

1. PLC (Programmable Logic Controller)

• Receives signals from various sensors (temperature, flow, level, photoelectric, encoder, etc.).
• Executes sequential control: cleaning → cutting → cooking → grinding → packaging.
• Integrates alarm systems and fault-switching logic for automatic downtime in case of issues.

2. HMI (Human-Machine Interface)

• Allows operators to set parameters via a touchscreen: cooking temperature, time, motor speeds, etc.
• Displays real-time operation status, alarms, and performance statistics.

3. Frequency Inverter Control (Longi 900 Series)

• Controls the speed of motors in equipment such as the conveyor, cutting machine, chili paste machine, and filling machine.
• Provides soft start, stepless speed regulation, and overload protection, ensuring longer equipment life.
• Allows precise adjustment of flow rates, coordinated with the PLC for a closed-loop system.

Example Promotion: The Rongji 900 Series Frequency Inverter uses advanced vector control technology, supporting V/F and FOC vector control, with multiple industrial network protocols such as Modbus, Profibus, and Profinet. It offers quick response times, strong anti-interference capabilities, and excellent flexibility, making it an ideal choice for food processing equipment that requires precise flow, torque, and load adjustments. It can save up to 20-30% in energy, reducing operating costs and maintenance needs.

4. Temperature Control System

• Multiple temperature probes monitor cooking conditions, with feedback to the PID controller.
• The PLC uses PID adjustment to control steam valves or electric heating power, maintaining a constant temperature within ±1-2°C.

5. Flow and Level Control

• Water flow for cleaning and spraying is regulated by the frequency-controlled pumps, optimizing water use.
• The sterilization system uses level control sensors to ensure the correct liquid levels are maintained.

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4. Control Workflow and System Principles

4.1 PLC Master Logic Architecture

1. Initial diagnostics → Reset all equipment.
2. Set parameters via HMI.
3. Start the sequence by pressing the “Start” button.
4. Cleaning → Cutting → Cooking → Grinding → Filling → Packaging.
5. Critical sensors (temperature, weight, flow) monitor performance and stop the system if any issue is detected.
6. Data is recorded for traceability.

4.2 Variable Regulation and Protection

• Temperature Deviation: PID control adjusts heating power; deviations beyond ±5°C trigger alarms and stop the system.
• Flow Speed Abnormality: Encoders and inverters monitor the speed; if deviations persist for over 10 seconds, the system halts.
• Filling Weight Deviation: Weight sensors ensure accurate filling; deviations beyond ±2% trigger alarms.

4.3 Equipment Protection

• The frequency inverter provides protection against overload, undervoltage, short circuits, and overheating.
• The PLC monitors emergency stops, door locks, and temperature extremes, halting operations immediately if necessary.
• Faults are automatically reported and logged for further troubleshooting.

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5. Material Selection for Control System

5.1 Frequency Inverter Selection

• Rongji 900 Series Frequency Inverter:
  • Stable performance with high dynamic V/F and FOC control.
  • Compatible with Modbus RTU, Profinet, and EtherCAT, allowing easy integration with PLC systems.
  • Built-in motor protection features, extending system life.
  • Energy-saving up to 20-30%, significantly reducing operational costs.

5.2 Motors and Sensors

• Food-grade, waterproof motors, paired with the frequency inverter for speed control.
• Temperature Sensors: PT100 or thermocouple types for high-temperature resistance.
• Level Sensors: Capacitive or ultrasonic types for high accuracy in sterilization tanks.

5.3 Piping and Materials

• The entire system uses SUS304 or SUS316 stainless steel for food-grade safety, easy cleaning, and corrosion resistance.
• All parts in contact with chili peppers are designed for easy disassembly and cleaning.

5.4 Electrical Control and Distribution

• Control cabinets made from cold-rolled steel or stainless steel, meeting IP protection standards.
• Circuit breakers, grounding protection, and surge protectors are incorporated.
• Remote monitoring capabilities for integration with MES/SCADA systems.

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6. Advantages of Longi 900 Series Frequency Inverter in the System

The Rongji 900 Series Frequency Inverter is perfectly suited for controlling equipment in chili pepper processing lines due to its advanced features:

• Application: Ideal for motors with variable speeds and torque requirements, such as conveyors, grinders, and pumps.
• Performance: Offers rapid response with steady output, capable of handling sudden load changes without destabilizing operations.
• Communications: Features Modbus, Profibus, Profinet, and Ethernet for seamless PLC integration.
• Maintenance: Built-in protection features minimize system downtime, enhancing reliability.
• Energy Efficiency: Energy savings up to 30%, leading to lower operational costs.

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7. Conclusion and Suggested Learning Path

1. Understanding the Process: Familiarize yourself with each step of the production line, from cleaning to packaging, and the risks involved at each stage.
2. Equipment Coordination: Recognize how each piece of equipment contributes to the overall flow, reducing downtime and optimizing efficiency.
3. Automation System: Understand how the PLC, HMI, frequency inverter, and sensors work together to ensure smooth operations.
4. Material Selection: Make sure you choose high-quality components like the Rongji 900 Series Frequency Inverter, which ensures system longevity and reduces operating costs.
5. Learning Path:
   • Study the equipment manuals and PLC programming.
   • Visit production lines for hands-on experience.
   • Attend supplier training for a deeper understanding of the Longi 900 Series Frequency Inverter.
   • Conduct simulations and optimize PID parameters to improve system response.

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1. Product Overview and Working Principle

The RG148 series from ebm-papst utilizes EC (Electronically Commutated) motor technology, integrating a rectifier, inverter, and a brushless DC (BLDC) motor into a compact unit. Instead of using a traditional AC induction motor and external variable frequency drive (VFD), these fans convert AC mains to DC internally and use an IGBT inverter to generate three-phase PWM signals that drive the motor.

Key Advantages

• High Efficiency: No belt or rotor copper loss; system efficiency >90%.
• Brushless & Maintenance-Free: No mechanical commutation—electronic switching replaces brushes.
• Easy Speed Control: A simple 1–6 kHz PWM or 0–10 V analog input allows linear speed regulation.

These fans are ideal for applications requiring wide speed ranges, low maintenance, and energy savings of up to 30% compared to traditional setups.

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2. Connector Definitions and Wiring

The fan features a 5-pin control connector alongside L/N/PE power terminals. The connector is typically an AMP MATE-N-LOK or Molex Mini-Fit Jr. housing, with pin numbers (“1–5”) molded into the plastic shell.

Pin	Wire Color (Original Harness)	Function	Description
1	Blue	GND (Signal Ground)	SELV ground, isolated from chassis
2	Yellow	PWM IN / 0–10 V	1–6 kHz square wave; >20% for startup, >5% for run
3	—	N.C. (Not Connected)	Reserved
4	White	Tach Out	2 pulses/rev, open-collector output
5	Brown	+18 V Output	Max ~20 mA, for pull-up or optocoupler supply

How to identify pins:

1. Visually inspect the connector for molded pin numbers or orientation notch.
2. With power applied, use a multimeter: the only stable ~18 V pair indicates Pin 1 (GND) and Pin 5 (+18 V).
3. Injecting PWM into Pin 2 should spin the fan—this helps verify its identity.

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3. Minimal Wiring for Testing

Power Side: Connect L/N to 230 V AC (or 115 V for low-voltage variants). Add a 6 A slow-blow fuse. PE must be grounded for safety.

Control Side (minimum 3 wires):

• Pin 1 → Connect to your microcontroller or function generator GND
• Pin 2 → Feed a 0–5 V PWM signal through a 1 kΩ resistor
• Pin 4 / Pin 5 → Optional; leave unconnected during basic testing

Startup Procedure

1. With the fan powered off, complete wiring.
2. Power on with PWM = 0%.
3. Output a 30% duty PWM (e.g. 3 kHz); the fan should spin up smoothly.
4. Adjust duty cycle and observe speed changes.
5. Set PWM <3% to stop the fan.

This minimal setup allows safe testing without needing feedback circuits.

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4. Tuning Parameters and Performance Verification

Parameter	Recommended Value	Purpose
PWM Frequency	2–4 kHz	Avoids audible noise
Startup Duty	≥25%	Ensures soft start
Minimum Duty	>5%	Fan stops below this value
RPM Calculation	rpm = freq × 30	Based on Tach signal (2 p/rev)

By measuring the Tach frequency and correlating it with airflow or pressure, you can build a duty-RPM-airflow map for system tuning or PID feedback control.

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5. Common Faults and Troubleshooting

Symptom	Possible Cause	Check / Solution
No rotation	PWM <20%; no GND; internal fuse blown	Oscilloscope on Pin 2; verify Pin 1–5 = +18 V; check fuse
Whining or jittering	PWM freq too low; sharp duty changes	Set to 2–4 kHz; ramp the duty smoothly
No Tach pulse	Missing pull-up or overvoltage	Pull up Pin 4 to +18 V with 10 kΩ or use voltage divider
Overheat shutdown	Poor ventilation; ambient >60°C	Clean airflow path; reduce speed/load
EMI interference	Long unshielded wires	Use shielded twisted pairs; add 100 Ω damping resistors on Pin 2/4

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6. Maintenance and Advanced Configuration

• Routine Check: Every 3 months, clean the impeller and check grounding screws; test insulation yearly.
• Cable Management: For >1 m signal wires, use shielded twisted pairs and ground the shield at one end.
• EEPROM Configuration: Use ebm-papst EC-Control software via Bluetooth or RSB bus to tweak internal parameters (e.g. soft-start ramp, min RPM).
• Harmonic Filtering: For multiple fans on a shared supply, consider adding filters or 12-pulse rectifiers to reduce THDi.

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7. Conclusion

The RG148 EC fan series represents a highly efficient and compact solution for modern ventilation systems. With its integrated inverter and brushless motor, it provides wide-speed-range performance without external VFDs. By mastering the 3-wire minimal control method, understanding PWM tuning, and applying basic troubleshooting, engineers can easily integrate and commission these fans in test setups and production lines. For advanced applications, feedback via Tach signals and EEPROM customization further enhances control accuracy and energy efficiency.

This guide aims to provide a comprehensive, practical overview to help users get the fan up and running safely, optimize its performance, and resolve common issues in real-world scenarios.

1. Overview and Requirements of the Packaging Rope Production Line

The packaging rope production line is widely used for processing polypropylene (PP) and polyethylene (PE) materials. It primarily involves extrusion, stretching, twisting, and winding to produce the required packaging ropes. The production line involves several motors, heating control, tension control, and synchronization control. The stability and precision of the equipment are critical for production efficiency and product quality.

Main Equipment:

1. Extruder: Used for melting and extruding the raw material into a uniform melt.
2. Drawing Machine: Used for stretching the cooled fibers to increase strength and elasticity.
3. Twisting Machine: Used for twisting the stretched fibers into ropes.
4. Winding Machine: Used for winding the finished ropes into coils.

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2. Control System Design

1. Motor Control and Inverter Selection

Motor control is essential for precise production on the line. The speed of each device’s motor must be adjusted in real-time to meet the production process’s requirements. Longi 9000 series inverters will be used to control the speed of each motor.

Extruder Motor Control:

• Motor Power: Typically, 15-55 kW asynchronous motors are selected.
• Inverter Model: Longi 9000 series inverters are suitable for high-power motors, providing precise speed control.
• Wiring Method: The inverter’s input is connected to a three-phase power supply, and the output is connected to the motor terminals via cables, usually using a star connection for stable starting torque and reliability.

Extruder Motor Parameter Settings:

• Frequency Range: 0-60Hz (can be adjusted depending on production requirements, typically set at 30Hz).
• Acceleration/Deceleration Time: Set to 5-10 seconds for smooth starting and stopping, avoiding overload.
• Current Limiting: Set to 120% of rated motor current as protection.

Drawing Machine Motor Control:

The drawing machine is used to stretch the fibers, and its speed is directly linked to the extruder’s output speed. The drawing machine inverter will be synchronized with the extruder inverter.

• Motor Power: Typically, 5-15 kW asynchronous motors are selected.
• Inverter Model: Longi 9000 series inverters.
• Wiring Method: Similar to the extruder inverter, connected via bus for synchronized control.

Drawing Machine Motor Parameter Settings:

• Frequency Range: 0-100Hz to match stretching speed with the extruder.
• Acceleration/Deceleration Time: Set to 5-10 seconds to avoid fiber breakage from fast stretching.
• Speed Synchronization: Use the inverter’s multi-machine synchronization function to keep the drawing machine synchronized with the extruder.

Twisting Machine and Winding Machine Motor Control:

Both the twisting machine and winding machine require precise speed control, especially for tension control under different conditions.

• Motor Power: Twisting machine typically uses 2-5 kW motors, and winding machine uses 5-15 kW motors.
• Inverter Model: Longi 9000 series for precise speed regulation and starting/stopping control.
• Wiring Method: Standard three-phase connection, with the inverter connected to the motor.

Twisting Machine Motor Parameter Settings:

• Frequency Range: 0-60Hz.
• Acceleration/Deceleration Time: Set to 3 seconds for smooth twisting.
• Synchronization Function: Achieved through PLC coordination with the drawing and winding machines.

Winding Machine Motor Parameter Settings:

• Frequency Range: 0-60Hz, closely related to fiber tension.
• Acceleration/Deceleration Time: Set to 5 seconds for uniform winding.

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2. Heating Control System and Temperature Regulation

The heating system in the extruder is crucial for maintaining material quality. Temperature control must be precise. We will use Longi PLC (LX1000 series) along with temperature control modules to monitor and adjust the temperature.

Extruder Temperature Control Design:

• Heating Zones: The extruder has multiple heating zones, each equipped with a temperature control module to monitor and adjust the temperature.
• Wiring Method: The temperature control module’s output is connected to the heater, and the PLC adjusts the temperature using analog outputs (4-20mA).
• Temperature Sensor: Use PT100 sensors with an accuracy of ±0.5°C to provide real-time temperature feedback to the PLC.

Temperature Control Parameter Settings:

• Set Temperature Range: Typically set at 180-220°C for different zones, suitable for PP and PE melting temperatures.
• Temperature Adjustment Strategy: Use PLC’s PID control algorithm to maintain precise temperature, avoiding overheating or cooling, which may cause instability in the material quality.

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3. Tension Control System

Precise tension control is essential during the drawing and winding processes to prevent fiber breakage or uneven winding. We will integrate tension sensors with the Longi PLC to implement real-time tension monitoring and control.

Tension Control Design:

• Tension Sensors: Select high-precision tension sensors like the FMS series, installed at key points on the drawing and winding machines for real-time feedback.
• Control Method: The PLC receives signals from the tension sensors and adjusts the drawing and winding speeds to maintain consistent tension.
• Wiring Method: The tension sensors provide analog signals to the PLC, which adjusts the motor speeds for closed-loop tension control.

Tension Control Parameter Settings:

• Target Tension Range: Set between 0.5-2kg to ensure stable fiber stretching and winding.
• Feedback Method: PLC adjusts the drawing and winding machine speeds based on the tension feedback from sensors.

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4. Synchronization Control Scheme

Synchronization control between multiple devices is essential for smooth production. We will use Longi PLC’s high-speed counters and pulse output features to synchronize devices.

Synchronization Control Design:

• Master and Slave Synchronization: The extruder will be the master device, while the drawing machine, twisting machine, and winding machine will be slaves. The PLC will synchronize these machines via pulse output.
• Wiring Method: The PLC sends pulse signals to all devices using high-speed counters to synchronize their operation.
• Synchronization Adjustment: The PLC adjusts each device’s speed according to the main device’s status, ensuring coordinated operation.

Synchronization Control Parameter Settings:

• Synchronization Pulse Frequency: Set to 50Hz to synchronize all devices.
• Precision Requirements: The PLC’s pulse output precision is set to 1ms to ensure synchronization accuracy.

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3. System Architecture and Wiring Diagram

Below is the basic wiring and architecture diagram for the packaging rope production line control system:

Equipment Connection and Wiring Diagram:

[Raw Material Mixer] → [Extruder] → [Cooling Tank] → [Drawing Machine] → [Twisting Machine] → [Winding Machine]
       ↑                ↑                ↑               ↑
       |                |                |               |
   [Longi PLC] ←→ [Longi 9000 Inverter] ←→ [Temperature Control Module] ←→ [Tension Sensors]

System Architecture Diagram:

              +------------+                +-------------+
              |  Longi PLC  | ←--> [Inverter] ←--> [Motor] ←--> [Device]
              +------------+                +-------------+
                     ↑                            ↑
                  [Sensors] ←--> [Tension Control] ←--> [Heating Control]

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4. Conclusion

By integrating Longi 9000 series inverters, LX1000 series PLCs, and Longi plastic machine configuration software into the packaging rope production line, we can achieve precise motor control, temperature regulation, tension control, and synchronization control, ensuring efficient and stable production. The design is clear and logically sound, meeting the needs of modern packaging rope production lines for automation and intelligence.

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1. Application Background and Industry Pain Points

In enclosed or semi-enclosed environments such as underground parking lots, automobile repair workshops, welding workshops, paint booths, and other industrial sites, harmful gases like carbon monoxide (CO), emitted from vehicle exhaust, fuel combustion, or industrial processes, can accumulate over time. This presents a health risk to workers and affects the quality of air. Therefore, an intelligent, automated ventilation control system is needed to monitor and regulate air circulation in real time.

Traditional ventilation systems mostly run at fixed speeds, which are simple but result in high energy consumption, low efficiency, and slow response to fluctuating CO concentrations. To address these issues, this solution designs an intelligent ventilation system based on Longi 900 Series Variable Frequency Drives (VFD) and RKC PID controllers for automatically adjusting fan speed using PID closed-loop control, ensuring good air quality in a variety of settings.

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2. System Components and Working Principles

1. Key Components

Module Category	Product Selection	Function Description
VFD (Variable Frequency Drive)	Longi 900 Series VFD	Controls fan speed, adjusts airflow rate automatically
PID Controller	RKC CH102 or REX-C100	Receives CO sensor input and outputs control signals (4-20mA)
Carbon Monoxide Sensor	ZE25-CO (Winsen)	Detects CO concentration in real time, outputs analog signals
Ventilation Equipment	Centrifugal Fan or Duct Fan	Regulates exhaust air according to VFD adjustments
Control Panel	Custom-made	Displays status, allows manual/automatic switch

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2. Control Logic and Operation Principles

(1) CO Concentration Detection

The CO sensor (e.g., Winsen ZE25-CO) continuously monitors the CO concentration in the air, typically outputting a 4-20mA analog signal. When the concentration exceeds a set threshold, it triggers subsequent control actions.

(2) PID Controller Adjustment

The RKC PID Controller compares the actual CO concentration with the set target concentration (e.g., 30ppm) and calculates the required adjustment signal using proportional-integral-derivative (PID) logic. It then outputs a control signal (4-20mA).

(3) VFD Speed Regulation

The Longi 900 Series VFD receives the analog control signal from the PID controller and adjusts the fan motor speed accordingly. For example, if the CO concentration is high, the PID controller will instruct the VFD to increase the speed, thereby increasing the airflow for faster exhaust.

(4) Feedback and Protection

The system continuously monitors CO concentration, and when it exceeds a safe level, the fan speed is increased automatically. Once the concentration drops back to a safe level, the fan speed is reduced to the minimum. This process optimizes energy use while ensuring the safety of workers.

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3. Longi 900 Series VFD Advantages

Feature	Description
PID Control Support	Built-in PID control parameters for automatic regulation based on external input
Flexible Analog Input Interfaces	Supports 0-10V, 4-20mA, and other input signals, adaptable to various control needs
High Reliability	Multiple protection features including overload, overvoltage, and overheat safeguards
Energy Efficiency	Wide speed regulation range (0-500Hz), enabling precise fan speed adjustments to reduce energy consumption
Ease of Maintenance	User-friendly interface, easy to maintain, and extend device lifespan

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4. Suggested System Configuration

Name	Model	Quantity	Description
VFD	Longi 900 Series 900-0015G3 (1.5kW)	1 unit	Drives the fan, adjusts speed according to PID control signals
PID Controller	RKC CH102	1 unit	Receives CO sensor signal, outputs control signal (4-20mA)
CO Sensor	Winsen ZE25-CO	1 unit	Detects CO concentration, outputs analog signal
Fan and Motor	YVF2 1.5kW + Centrifugal Fan	1 set	Core of the system, performs exhaust tasks
Control Panel	Custom-made	1 unit	Includes operation buttons, display indicators, emergency stop

Suggested Parameter Settings

For Longi 900 Series VFD, the following parameters are recommended:

Parameter	Description	Suggested Value
F0-00	Command Source	1 (External Terminal Control)
F0-01	Main Frequency Source	2 (AI1)
F5-02	PID Feedback Source	1 (Analog Input)
F5-08	Sensor Type	1 (4-20mA)
F5-01	PID Setpoint	30ppm (Reference Value)
F0-04/05	Acceleration/Deceleration Time	5-10s

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5. System Deployment and Maintenance Recommendations

1. Installation and Layout

• Sensor Installation: CO sensors should be installed in central locations or at the end of exhaust ducts, approximately 1.5-2 meters above the floor, to ensure complete area monitoring.
• PID Controller: Should be installed in a location visible to the operator for easy adjustment of parameters.
• VFD and Fan Installation: VFD should be installed in an electrical control cabinet with adequate ventilation, avoiding high temperatures and humidity.

2. System Debugging and Operation

• Before powering up, verify that the wiring is correct, especially ensuring that the VFD output terminals (U/V/W) are not connected to the mains.
• Set the RKC PID Controller:
  • Setpoint (SV) to 30ppm.
  • Control mode to PID, output signal set to 4-20mA.
• After connecting the CO sensor, adjust PID parameters (proportional, integral, and derivative gains) for optimal system response.

3. Maintenance and Upkeep

Equipment	Maintenance Task	Frequency
CO Sensor	Zero-point calibration and functionality check	Every 6 months
PID Controller	Output signal and display check	Every 12 months
VFD	Heat sink cleaning and electrical check	Every 12-18 months
Fan Motor	Lubrication and current measurement	Every 3-6 months

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6. System Upgrades and Expansion Recommendations

1. Remote Communication Module

The Longi 900 Series VFD supports Modbus RTU communication. Add a remote communication module for cloud-based monitoring, data logging, and alarm notifications, enabling more advanced smart management.

2. Multi-Region Control

For large workshops or parking lots, deploy multiple independent ventilation units, each with its own CO sensor, to control fan speeds regionally, optimizing energy use.

3. Integration of Particulate Matter (PM2.5/PM10) Sensors

Expand the system to monitor and control particulate pollution, ensuring air quality across various industrial processes.

4. Lighting System Integration

Incorporate lighting control, turning on both the lights and the ventilation system when personnel enter a room, and turning them off after a delay once they exit, further reducing energy consumption.

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7. Conclusion and Value Proposition

With the Longi 900 Series VFD, RKC PID Controllers, and CO Sensor Integration, this system enables automatic fan speed adjustment to ensure air quality and worker safety. By utilizing energy-efficient, smart control, this solution meets the needs of environments like workshops, parking garages, and industrial sites, and provides significant benefits in terms of energy savings, safety, and environmental health.

This system is an ideal solution for maintaining high standards of air quality while optimizing energy use in industrial facilities.

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The Fully Automatic Platen Die-Cutting Machine is a specialized device designed for die-cutting and creasing/creasing of flat sheet materials such as cardboard, corrugated paper, and laminated paper. It integrates the traditional “hand press” platen principle with automatic paper feeding, positioning, collecting, fault detection, and safety interlock systems for batch production of color boxes, cartons, wine boxes, labels, hangtags, and some thin plastic packaging products.

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I. Device Principle & Process Challenges

1.1 Basic Process of Platen Die-Cutting

Process Flow:
Paper Feeding → Positioning → Clamping & Conveying → Die-Cutting/Creasing → Waste Removal → Paper Collecting

Key Features & Challenges:

• High Inertia:
  320-ton machine requires the crank-link mechanism to decelerate and stabilize near the top dead center.
• Tight Timing Coupling Between Stations:
  Intermittent transport of the gripper bar is synchronized with the die-cutting stroke; any timing deviation risks paper tearing.

1.2 Control Key Points & Challenges

Key Points	Challenges	Solution Approach
Multi-Axis Synchronization (Feeder+Indexer+Platen)	Mechanical chain + intermittent cam cause rigid coupling; difficult to optimize speed curves.	Retain mechanical spindle; independent VFD speed control for Feeder. Gripper bar position identified via encoder Z-PULSE to avoid costly electronic cam reconstruction.
Registration & Repeatability	Paper stretching/static electricity, gripper bar spring fatigue.	Front/side guides + photoelectric correction; PLC checks X6/X7 every 10 ms, with high-speed interrupt correction.
Pressure Closed-Loop Control	320-ton hydraulic cylinder pressure drift of 2%.	FX3U-4AD module for 4–20 mA signal; PID regulates Y12 pressure-building valve PWM. Set Press OK = 0.95 × Setpoint.
Safety Category 3	Over 20 door switches + light curtains; often bypassed on older machines.	Pilz PNOZ X3 + safety relay dual-loop; real-time link status display on HMI.

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II. System Configuration Bill of Materials

Category	Selection	Key Parameters/Quantity
PLC	Mitsubishi FX3U-80MT/ES-A	80 I/O, transistor sink output; expansion modules: FX3U-4AD-PT-DA, FX3U-485-BD
HMI	Delta DOP-B10S411 (10.4″, 800×600)	COM1→PLC RS-422; COM2→VFD (Modbus-RTU)
VFD	Inovance MD200-11k-4	Supports 0–10 V analog input + RS-485 monitoring
Servo Drive	Leadshine EL7-750 + 0.75 kW Motor	Indexer drive, 5000 ppr encoder
Safety	Pilz PNOZ X3 ×1, SICK Light Curtain ×2	2 N/C 2 N/O outputs, 24 V DC
Low-Voltage Distribution	Schneider NSX80N+GV2, Phoenix 24 V/10 A PSU	—
Sensors	Panasonic CX-400 Series Photoelectric (12), Ultrasonic Double-Sheet Detector ×1	NPN output
Actuators	Airtac 4V210-08 Solenoid Valves (18), HYDAC Pressure Sensor 1.0–25 MPa	—

Electrical Architecture Overview:

┌──── Pilz PNOZ ────► KM1 / KM3 / STO三相380  ▣         └─> MCB → VFD → Main Motor                │                 ┌─ Encoder                ▼                 ▼              PLC FX3U ──485─── MD200 (VFD)                │RS-422                ▼          Delta HMI DOP-B10S411                │                ├── DO → Sol/Contactor                └── AD → Press Sensor

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III. Control Logic & Program Architecture

3.1 Task Allocation

Program Segment	Function	Key Components
P0 – Start/Emergency Stop	Main contactor, E-stop chain	X0, X1, X2 → Y0, Y1
P1 – Paper Feeding & Registration	Feeder VFD, double-sheet detection, front/side guides	X4–X7, X35 → D400 PID, frequency control
P2 – Gripper Bar	Clamping cylinders, servo indexer	Y5, Y6, Y7, M404 interrupt
P3 – Die-Cutting	Platen servo, pressure closed-loop	Y10, Y11, Y12 → D410 PID
P4 – Paper Collecting	Lifting motor, counter	Y14, Y15, D200 piece counter
P5 – Alarm	Tower light, buzzer, HMI alarm codes	X16–X22, Y16, Y20, Y21

3.2 Main State Machine (S-Bits)

• S000 IDLE
• S010 FEED_READY
• S020 REGISTER
• S030 PRESS
• S040 DELIVERY
• S050 PAUSE / FULL
• S060 ALARM_STOP

All transition conditions are annotated in the CSV instruction list.
High-Speed Interrupt M8252 captures front-guide OK signal every 10 ms to set D404 for auxiliary correction.

3.3 HMI Screen Planning

Screen No.	Theme	Key Objects/Components
00	Welcome / Machine Status Overview	Speed gauge, production count, current job
01	Auto Run	Start/Stop, speed setting, graphical timing bar
02	Settings	Front-guide fine-tuning (±0.1 mm), pressure setting (kN), batch stop count
03	Manual/Test Run	Jog buttons, I/O indicators, simulated teaching
04	Alarm	Alarm code, text description, handling guide
05	System	User permissions, I/O calibration, maintenance hours

HMI Macro Example (Front-Guide Fine-Tuning):

; Macro No.11  Front-Guide +0.1 mmREADWORD  d100,   &H0004  ; Read current front-guide position from D100ADD       d100,   &H0001WRITEWORD d100,   &H0004

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IV. I/O Allocation & Program Files

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V. Enhancements & Future-Proofing

Electronic Cam Retrofit

• Replace mechanical spindle with servo + absolute encoder for virtual spindle + electronic scale registration to achieve speeds up to 5,500 sph.

MES Data Interface

• PLC reports production data to ERP via FX3U-ENET-AD module; add QR code scanning for job change on HMI.

Predictive Maintenance

• Connect key bearing and oil temperature sensors to FX3U-4AD; generate maintenance tasks automatically when runtime exceeds limits.

Safety Upgrade

• Replace single light curtains with SIL 2 extended versions for automatic restart inhibition; add safety STO (VFD) to E-stop.

Energy Recovery

• Retrofit main motor with torque-type servo + DC bus feedback for 8–12% energy savings.

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VI. Project Implementation Milestones

Period	Deliverables	Notes
T0+1 Week	Project Initiation & Electrical Scheme Confirmation	BOM, IO list v1.0
T0+3 Weeks	Electrical Cabinet Drawings / PLC-HMI Program Alpha	CAD PDF + 80% program functionality
T0+5 Weeks	On-Site Assembly & Cold Commissioning	IO point-to-point, drive self-learning parameters
T0+6 Weeks	Hot Commissioning Trial Production (10 h)	Speed curve optimization, quality confirmation
T0+7 Weeks	FAT & Documentation Delivery	Chinese/English manuals, source code, backup images

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Key Takeaways Highlighted in Bold:

• Multi-Axis Synchronization: Mechanical spindle retained for cost efficiency; Feeder VFD and encoder Z-PULSE ensure precise gripper bar timing.
• Pressure Closed-Loop Control: PID-regulated hydraulic pressure for consistent die-cutting quality.
• Safety: Pilz PNOZ X3 + safety relay dual-loop prevents bypassing; real-time status display on HMI.
• Future-Proofing: Electronic cam, MES integration, predictive maintenance, safety upgrades, and energy recovery ensure long-term competitiveness.