1) Do I have to use multiple Modbus_Comm_Load for each slave device with each Modbus_Master block? What if I use the same instance DB block from Modbus_Master for all of the different Modbus_Master(for each slave)? I'm not sure if I have to use the same Instance block or I have to create an new instance block for Modbus_Master.

2) Does the Modbus_Comm_Load 'Req Input' only need to be scan only on first cycle or always true. The Req paramater for Modbus_Master block is a bit confusing too. When should you set it to true if you have multiple Modbus_Master block for different slave device? Does it need to be true in sequence until status done and move to next block or can I set it cycle every 100ms or 1 sec? I wonder if there would be any conflict if that happen?

Thanks