I need to communicate two PLCs, the first one is an S71200 PLC (slave), the other is a Modicon TM221 PLC (Master), I have made the configuration in both PLCs, and I have tested them separately using the ModBusPool software, and it works normally, however, in the communication tests between both PLCs, the link is established, but there is no data exchange, please if someone can give me a clue as to what may be happening, 

Thanks

Hello,

in your screen it looks like inverted functionality - S7-1200 like Client and Modicon probably as Server. What data did you tested with poll SW as executed ok? I can help you only with S7-1200 side. I recommend bypass Modicon in this time and connect poll SW as Server to your S7-1200. This is priority for you this time. If you'll have all situations tested ok, then you can attach to net Modicon. After this you'll have better diagnostic in case of not functionality.

Update: I see your situation (as from picture of S7-1200) that S7-1200 is Client and Modicon is Server. With this cfg if you want test functionality of each PLC with poll SW, you need poll SW run as Server with S7-1200 and as Client with Modicon PLC. Can you confirm this sequence?