24.05.2018, 09:50
Hi.
Im trying to interface to some Modbus devices that have internal parameters that are only accessible with a non-standard Modbus telegram. (Function codes 101 and 102)....
It looks pretty easy to manually create these nonstandard Modbus commands and drop them into the RS485 port but how are the CRC codes calculated? That bit has got me at the moment. Anyone with any pointers?
Im trying to interface to some Modbus devices that have internal parameters that are only accessible with a non-standard Modbus telegram. (Function codes 101 and 102)....
It looks pretty easy to manually create these nonstandard Modbus commands and drop them into the RS485 port but how are the CRC codes calculated? That bit has got me at the moment. Anyone with any pointers?