Hello,

We are trying to connect two PLC's where one of them has set operating mode as IO Device. The IO controller is S7 1500 ( 515-2AM02-0AB0 V2.9 ) and IO device is S7 1200 ( 214-1AG40-0XB0 V4.5 ), along with some additional IO modules. Tia portal V17 Upd 6.

In general communication works well, but if the IO controller is switched off and then back on, while the IO device is kept on, communication will not resume after the IO controller is up and running again. Communication resumes if the IO device is power cycled or if ethernet cable toward the IO device is disconnected and connected back again.

Attached diagnostic buffer from IO device and IO controller.

 What can be the cause for this behaviour ?

Best regards

Hello,

your both HWs have not required diagnostic OBs included/downloaded.

Hello,

As far as I know all the available blocks have been added to the project.  (attachment)

Best regards

Hello,

it is clear that more other OBs are there available, also HW interrupt OB but from your IO device is event that it is inside STOP mode. It needs to be everytime in RUN so try also change system inside options that it will always go to RUN mode not STOP or previous one. This is all what I can recommend to you.