How to monitor values inside addresses in PLC using Unity Pro S?


I am not very familiar with PLC software, but I was trying to test communication between an HMI and a Schneider PLC. I wanted to write to a PLC address from the HMI, say %MW300, and then monitor that address in the PLC to make sure the value changes to what I set it to from the HMI. I was able to establish communication from the HMI to the PLC via simulation, but inside Unity Pro S I wasn't sure how to monitor the values/addresses inside of the PLC to confirm. Hopefully this description makes sense and the solution is actually rather simple? Thanks