Dear user,

Let me show you our blog post where we introduce the better way to communicate both modules: 

In this case, the example uses an Ardbox PLC model but the way to communicate PLC and WiFi module is exactly the same (Also both programs can work for you without changing anything).

You can use it in a different ways but we recommend that on the PLC site, we take all the data from inputs/communications and we control the Outputs/communications. All this information will be given/sent by the WiFi & BLE module, which is the Gateway (sends and receives the information via WiFi to the Web Server/Application/...

You will get a better idea taking a look at the previous link. 

Anything you may need, please let us know without any problem, 

have a nice day!