Inverter-VFD PG card for Interface-communication to PLC-Encoder

Inverter-VFD PG card for Interface-communication to PLC-Encoder

To integrate a Variable Frequency Drive (VFD) with a PLC and an encoder using a PG (Pulse Generator) card for interface communication, you need to consider several aspects. Here’s a guide on the general setup, common components, and the typical workflow for such an integration:

Components and Considerations

1. Variable Frequency Drive (VFD):
   • The VFD controls the motor speed and torque by varying the input frequency and voltage.
   • It should have a compatible PG card slot for encoder feedback.
2. PG Card (Pulse Generator Card):
   • This card interfaces with the encoder and provides feedback to the VFD for precise speed and position control.
   • Common PG cards include models from Mitsubishi, Siemens, Yaskawa, and others, each compatible with specific VFD models.
3. Encoder:
   • Provides real-time feedback on the motor’s position, speed, and direction.
   • Types include incremental and absolute encoders, with incremental being the most common for VFD applications.
4. PLC (Programmable Logic Controller):
   • Acts as the central control unit for automation, processing inputs, and controlling outputs.
   • It needs to communicate with both the VFD and the encoder, often using protocols like Modbus, Profibus, Profinet, or Ethernet/IP.

Workflow for Integration

1. Select Compatible Components:
   • Ensure the VFD, PG card, encoder, and PLC are compatible with each other.
   • Check the specifications and documentation for compatibility, especially the communication protocols and electrical interfaces.
2. Install the PG Card in the VFD:
   • Power off the VFD before installation.
   • Follow the manufacturer’s instructions to insert the PG card into the designated slot.
3. Connect the Encoder to the PG Card:
   • Use appropriate cabling to connect the encoder’s output to the PG card inputs.
   • Ensure correct wiring for power, signal, and ground connections as per the encoder and PG card specifications.
4. Connect the VFD to the PLC:
   • Use the appropriate communication interface (e.g., RS485 for Modbus, Ethernet for Profinet) to connect the VFD to the PLC.
   • Configure the communication settings on both the PLC and the VFD to ensure proper data exchange.
5. Configure the PLC:
   • Set up the PLC to read the encoder feedback from the PG card via the VFD.
   • Program the PLC to control the VFD based on the encoder feedback, implementing necessary logic for speed, position, and torque control.
6. Parameter Settings in VFD:
   • Configure the VFD parameters to accept the PG card inputs and utilize encoder feedback for control.
   • Refer to the VFD’s manual for detailed parameter settings specific to the PG card and encoder integration.
7. Testing and Calibration:
   • Power on the system and perform initial testing to ensure communication and control are functioning correctly.
   • Calibrate the system by running the motor at different speeds and positions, verifying the feedback accuracy and control response.

Example: Mitsubishi FR-A700 VFD with FR-A7AP PG Card and Incremental Encoder

1. Components:
   • VFD: Mitsubishi FR-A700
   • PG Card: Mitsubishi FR-A7AP
   • Encoder: Incremental Encoder
   • PLC: Mitsubishi FX or Q Series
2. Installation:
   • Install the FR-A7AP PG card into the FR-A700 VFD.
   • Connect the incremental encoder to the PG card using shielded cables.
   • Connect the VFD to the PLC using RS485 for Modbus communication.
3. Configuration:
   • Set the VFD parameters for PG card input and encoder feedback.
   • Configure the PLC communication settings to read data from the VFD and control motor speed based on encoder feedback.
4. Programming:
   • Write the PLC program to read the encoder data via the VFD and implement control logic.
   • Test the system and make necessary adjustments to ensure accurate control.

Conclusion

Integrating a VFD with a PLC and encoder using a PG card allows for precise motor control, essential in various industrial applications. Ensure compatibility between all components, follow manufacturer guidelines for installation and configuration, and thoroughly test the system to achieve reliable performance. For specific models and detailed steps, always refer to the respective product manuals and technical support resources.