Solution:

You will need to check the enable box at the top left. The IO in the -330 model is in port 1 whch is what we are going to select. The serial settings are as follows: 9600 baud, 8 bits, no parity, and 1 stop bit(8n1). Also check the Enable IO and XC-CNT extension box. The unit ID is the slave ID which you can change but for this example it is going to be left at the default of 240. I am using Modscan32 as my modbus master software. I set the Transmission Mode to Modbus ASCII, using the IP address of the router and on Service Port: 502. The addresses I want to read are 0x411 (AN1 value) and 0x413 (AN2 value). The received data is going to be a 12 bit value in decimal. Note: There is an offset of 1. So to read 0x411 (AN1) we will actually need to use 0x412 as shown in the example below. Address Space IO-CNT-Port1 Notes: If the XC-CNT board is absent all corresponding values are 0. Information about the XC-CNT boards can be found in the system log after starting the user module. Writing is possible to all registers. Writing to the registry, which is not disigned for writing, is always successful, however there is no physical change.