Troubleshooting serial com 3-3 – Yaskawa F7 Modbus User Manual
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Troubleshooting Serial COM 3-3
3.3:
Verify that the contents of the message adheres to the protocol format as described previously.
3.3.1: Verify that the node address is valid.
3.3.2: Verify that the function code is valid
3.3.3: Verify that the register address is valid
3.3.4: Verify that the number of data bytes is correct is valid
3.3.5: Verify that the CRC is correctly calculated.
3.3.6: Verify that the message requires a response.
4:
Verify the contents of the response message.
4.1:
Connect an oscilloscope between the controller RxD and GND.
4.1.1: Verify that the message pulse train exists and contains the correct number of pulses. Refer to the chapter
Message Formats for information on the message contents.
4.1.2: Verify that he signal levels adhere to the RS232 standard.
4.2:
Capture the response message sent by the controller in a hexadecimal format and record it below.
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4.3:
Verify that the contents of the message adheres to the protocol format as described previously.
4.3.1: Verify that the node address is valid.
4.3.2: Verify that the function code is valid
4.3.4: Verify that the number of data bytes is correct is valid
4.3.3: Verify that the register address is valid
4.3.4: Verify that the CRC is correctly calculated.