In one of my applications , ADVhmi talks to 8 controllers on serial Modbus .
I never connect controls on screen to PLC registers , rather use timed read function from drivers to read and write data .
response = {0}
ModbusRTUCom1.StationAddress = NumericUpDown1.Value
Try
response = ModbusRTUCom1.Read("400001", 63)
' move response array data to controller data array
Catch ex As Exception
End Try
' now change NumericUpDown1.Value to next controllers node address
response = {0}
ModbusRTUCom1.StationAddress = NumericUpDown1.Value
Try
response = ModbusRTUCom1.Read("400001", 63)
' move response array data to netx controller data array
Catch ex As Exception
End Try
' and so on .