Intercom communication between two ATEM 2 M/E Constellation

Hello, colleagues.
We have several 3 studios, in each studio there is a video mixer Intercom communication between two ATEM 2 M/E Constellation HD. I am wondering if it is possible to make intercom communication between them by means of standard SDI connecting them to each other?
We have several 3 studios, in each studio there is a video mixer Intercom communication between two ATEM 2 M/E Constellation HD. I am wondering if it is possible to make intercom communication between them by means of standard SDI connecting them to each other?