It's impossible to be sure, as we don't have enough context — but stritly speaking, there is a technical distinction between a 'bay' and a 'rack'; a 'bay' may contain several 'racks'.
However, in FR there is often confusion and the terms are often found interchangeably or reversed!
Here, because they are talking about a connection to some other remote panel, I'm suspecting this is possibly an actual 'bay', though it could equally well be just one rack within a larger bay. The inversion of the terms wouldn't actually be very serious in FR; they do also quite often use the EN term 'rack' when they really need to make a specific distinction.