Issue writing single coil (FCT 5) from AC500 to ABB 615 series relays in Modbus TCP/IP.
Dear All members,
We have an issue when we write from AC500 PLC (FCT 5) to single coils ABB REF615 protection relay in Modbus TCP/IP. After we try it, nothing happens to the REF615 binary outputs and it returns exception code 03 Illegal data value. It is really curious because when we write to same single coils from Modbus test program (ModScan or Modbus Poll), the control command is sent and executed successfully.
Is there something wrong or additional to take into consideration in Automation Builder/CODESYS program?
Project configuration (Automation Builder 1.2 version) and some information about Modbus REF615 relay are attached.
I appreciate your help.
PD: There is no problem reading values (holding register FCT 3).
Best regards,
Jose.Alejandro
We have an issue when we write from AC500 PLC (FCT 5) to single coils ABB REF615 protection relay in Modbus TCP/IP. After we try it, nothing happens to the REF615 binary outputs and it returns exception code 03 Illegal data value. It is really curious because when we write to same single coils from Modbus test program (ModScan or Modbus Poll), the control command is sent and executed successfully.
Is there something wrong or additional to take into consideration in Automation Builder/CODESYS program?
Project configuration (Automation Builder 1.2 version) and some information about Modbus REF615 relay are attached.
I appreciate your help.
PD: There is no problem reading values (holding register FCT 3).
Best regards,
Jose.Alejandro
Asked 1 month ago
Answers
0
If your write coil is success in Address 2052 from Modscan/Mod Poll (Default Offset 1), then you have to use address in AC500 like 2051 (Default Offset 0).
And also, as per Manual - Only one Modbus Control Operation is allowed. Hence, we should not try to write simultaneously to 2052 & 2053. It should be a separate write query for each control operation.
And your control operation should be configured as pulse command, do not try to write repeatedly value 1 to same coil, will result in exception response.
And also, as per Manual - Only one Modbus Control Operation is allowed. Hence, we should not try to write simultaneously to 2052 & 2053. It should be a separate write query for each control operation.
And your control operation should be configured as pulse command, do not try to write repeatedly value 1 to same coil, will result in exception response.
Answered 1 month ago
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