Hi,
I am constantly using S7 CB 1241 (RS485) Modbus comms to field devices, but these one was designed as a custom device. However I can see it with PC using Modbus Poll program. Also I can see other devices - that means, that wiring is ok. Problem appears when I just move wires to PLC, I still can see other devices get response, but from this device I get errors.
1) Initial setting reccomended from supplier and example. 9600 8n1 node 1
2) What do I see from Modbus Poll from the PC
3) Modbus Poll configuration on the PC
4) MB_MASTER instruction in S7
Every time MB_MASTER contacts node one, it gets error 8383, which means "Error in the data address or address outside the valid range of DATA_PTR"
If somebody could help me with translating this Raw Data Poll:
01 - node number
03 - function code
00X20 - register DEC 32 (is it 40032 or 400032 for function code 03?)
00 09 - quantityof registers (can start with 1)
84 06 - CRC16 - I am not sure if MB_MASTER instruction sends it automatically..
into S7 logic.... I need to get at least one word of feedback, then I can manage.
I am constantly using S7 CB 1241 (RS485) Modbus comms to field devices, but these one was designed as a custom device. However I can see it with PC using Modbus Poll program. Also I can see other devices - that means, that wiring is ok. Problem appears when I just move wires to PLC, I still can see other devices get response, but from this device I get errors.
1) Initial setting reccomended from supplier and example. 9600 8n1 node 1
2) What do I see from Modbus Poll from the PC
3) Modbus Poll configuration on the PC
4) MB_MASTER instruction in S7
Every time MB_MASTER contacts node one, it gets error 8383, which means "Error in the data address or address outside the valid range of DATA_PTR"
If somebody could help me with translating this Raw Data Poll:
01 - node number
03 - function code
00X20 - register DEC 32 (is it 40032 or 400032 for function code 03?)
00 09 - quantityof registers (can start with 1)
84 06 - CRC16 - I am not sure if MB_MASTER instruction sends it automatically..
into S7 logic.... I need to get at least one word of feedback, then I can manage.