I experience issue with V350 controlling two Modbus RTU Slaves – VFD and Flowmeter, connected in the same port. The code I attach works OK when both of the devices online.
The main issue is when I disconnect one of the devices from the network, and Modbus port (Function in Progress) gets stack and the PLC polls only the device that has been out of connection, while the other one – keeps unscanned. For example, when I shutdown the flowmeter (subroutine 8_FLOWMETER), I don’t get any data from VFD though it is online and OK.
Please advice how to organize Modbus network to avoid the port stuck on the offline device? Is there a way to terminate communication with offline Slave?
The software I use is 9.8.79 Build Beta 0, PLCs are V350 -35-TU24, VFD is Commander SK by Control Techniques, Modbus RTU via RS485 2-wire. Flowmeter is Russian SKG, manual is in Russian, so I didn’t attach it. Generally supports Modbus RTU, RS-485 2-wire