Christoff84
Lifetime Supporting Member + Moderator
I have a Field Electronics 1000 analog input module thats using modbus RTU to communicate via a B&B Electronics ESR902 serial to ethernet convertor, to a KEPware Kepserverex OPC server. The problem is that when I request more then 1 register of data from the slave, it replies with bad data.
Here's a good and bad example of what I'm getting.
Good:
TX: 02 03 0001 0001 D5F9 [Slave Address '02', Command '03' Read, Start at Register '0001', reply with '0001' registers, CRC 'D5F9']
RX: 02 03 02 3184 E9B7 [Slave Address '02', Command '03', # Bytes of data '02', Data '3184', CRC 'E9B7']
If I request more then 1 register I get:
TX: 02 03 0001 0004 15FA
RX: 02 03 08 3184 00 0D71 00 17B9 00 0759 F70E 00
The problem seems to be the extra '00' bytes its sending. I have no idea where they are coming from or why.
Anyone have any experience troubleshooting this type of error?
Here's a good and bad example of what I'm getting.
Good:
TX: 02 03 0001 0001 D5F9 [Slave Address '02', Command '03' Read, Start at Register '0001', reply with '0001' registers, CRC 'D5F9']
RX: 02 03 02 3184 E9B7 [Slave Address '02', Command '03', # Bytes of data '02', Data '3184', CRC 'E9B7']
If I request more then 1 register I get:
TX: 02 03 0001 0004 15FA
RX: 02 03 08 3184 00 0D71 00 17B9 00 0759 F70E 00
The problem seems to be the extra '00' bytes its sending. I have no idea where they are coming from or why.
Anyone have any experience troubleshooting this type of error?