AC450 controller -- CI532 V02 for MODBUS comm. ERR
we use CI532 V02 for the MODBUS comm. between AC450 (master) and customer slaves, but we cannot get PLC Status MS valid, we have set correct MVI1, Line Characteristics MS, Network Configuration MS and Register Addresses MS, and these 4 DB are valid. All hardwire link are checked and verified okay by using simulating MODSLAVE and MODSCAN.
It seems the AC450 cannot detect the salves, is there any good suggestion ?
or somebody has one good DB & PC as our reference,
Thanks in advance.
Best Regards / Juan Yu
Voted best answer
Is this a new connection or did something break ... ?
If it is a new connection, the PLC slaves MUST support the modbus poll command - FC7. The connection will not start unless the slave first replies to a poll message from the CI532. This sets the conection status to "good" and starts the communications to the slave.
If this used to work, then did you mess with anything in the MVI, MVN or MVC database elements ? Changing PLC adresses can break the link and prevent it from restarting. If you break the link like this you need to re-load the AC450 from a DUAP and restart. See the MVI manuals for details about what changes can require a controller restart.