Comm Loss (Adv. Code 0)

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This fault indicates a loss of communication when the drive is operating via a serial link. The time elapsed since the last Modbus communication exceeded the limit set in parameter 903 (SIO Timer). This can prevent external control or monitoring of the drive.

• Break in the serial communication cable (e.g., Modbus RTU, RS-485) due to mechanical damage or improper termination.
• Incorrect serial communication parameters (e.g., baud rate, parity, slave address) set on the drive (e.g., P9-01 Baud Rate, P9-02 Slave Add) or the master device.
• Exceeding the communication timeout limit (P9-03 SIO Timer) due to excessive network traffic or delays on the bus.
• Faulty serial communication module or port on the drive or the master controller.
• Noise or electromagnetic interference (EMI) on the communication bus disrupting data transmission.

Klikk på steg for å spore fremgangen.

1. 1

   1. Verify the physical integrity of the serial communication cable, checking for secure connections at both the drive's communication port and the master device.

2. 2

   2. Check and confirm that drive parameters P9-01 (Baud Rate), P9-02 (Slave Address), and P9-03 (SIO Timer) match the master device's settings.

3. 3

   3. Using a communication analyzer or diagnostic software, monitor the Modbus traffic to ensure the master device is sending requests and the drive is responding within the P9-03 timeout.

4. 4

   4. Verify proper termination resistors (e.g., 120 Ohm) are installed at both ends of the RS-485 bus segment.

5. 5

   5. Inspect the shielding of the communication cable and ensure it is properly grounded at one end to minimize EMI.

6. 6

   6. Replace the drive's communication option card or control board if all external communication components and parameters are confirmed correct.