Hi Everyone,
I'm working on a MODBUS routine for communication with one of our control modules. I'm using NI's Modbus library to initiate a connection, check the registers, etc then report the results back to a teststand seq for fruther analysis.
Problem? I made a few minor adjustments to the library (just the main routine) because i only need to read the registers for now. However, when I conenct with the TCP Open Connection, nothing happens. Well, not completely true.. I sinffed the connection with Ethereal and I get the following errors...
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1)
SENDING:
TCP: Src Port 2061, Dst Port: 502, Seq: 13, Ack: 10 , Len:12
Checksum: 02x282d [incorrect, should be 0xfd6b]
2)
RECEIVING:
Modbus/TCP:
-Modbus: Function 4: Read input registers. Exception: Illegal data address
exception code: Illegal data address (2).
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I understand the second one and believe it's related to the first but ....?
Does anyone have any ideas or suggestions? I'd go into the TCP OPEN.vi if I could, but it wont let me, so...?
Thanks Again,
BK
