CI867 and Modbus RTU Slave on daisy chain
I am using CI867 Module as Modbus Master module for polling the data at controller side.
We are using Moxa Gateway for Modbus RTU devices, there are multiple serial slaves that are communicating on daisy chain. These slave are connected to a port in daisy-chain(Multi-drop) to a converter on RS-485 interface.
Please tell how to configure the Modbus slave in this case at controller end.
Under Gateway how to define the slave ID. How slave ID is different w.r.t. Slave Position?
Function block types are used for master communication (and the Access Variable Editor is used for slave communication).
Add libraries (ModBusTCPCommLib, CI867ModbusTcpHwLib etc) to your project, connect them to your application, add connect HW library to the controller.
Insert a gateway unit on one of your two Ethernet ports on the CI867, and then add your slave units under the gateway (which represents your Moxa GW).
Address the gateway with correct ip-address. Slave position is corresponding to slave ID AFAIK.
After that define channel and partner id on your MBTCPConnect Function Block.
Observe that you might have to check Moxa Gateway settings, if you are using more than one serial port for the RTU units (in that case virtual or offset configuration might be used), see below.