There is OSN3500 with SSN1PQ1 and SSN2PQ1 used in one subrack. (This also refer to all NG-SDH, include OSN1500, OSN2500, OSN7500).
Can we create SSN2PQ1 as "PQ1" (not "N2PQ1") in T2000 in working slot and use it in TPS where protection board is physically SSN1PQ1 ("PQ1" in T2000)?
SSN2PQ1 can be created as "PQ1" or "N2PQ1" logically in T2000, because this board have Multi-ID function.
1. Usually, logical "PQ1"(N1PQ1) can not protect "N2PQ1", "N2PQ1" can protect "PQ1"(N1PQ1).
2. Using Multi-ID function of physical SSN2PQ1, we can create it logically as "PQ1"(N1) in T2000 in working slot of subrack. In this case SSN1PQ1 "PQ1" in protection slot of TPS can protect that "PQ1"(physical SSN2PQ1) that installed in working slot.
3. But it is not suggested to do like in item 2. Instead of that, it is bettter to install SSN2PQ1 in protection slot of TPS, then it can protect any SSN1PQ1 or SSN2PQ1 in working slots. If create SSN2PQ1 logically as "PQ1"(N1PQ1), it cannot support N2 new functions, but maybe customer in future will want to use them.
Usually, "PQ1"(N1PQ1) can not protect "N2PQ1", "N2PQ1" can protect "PQ1"(N1). But, if you create SSN2PQ1 as "PQ1"(N1) in T2000(this is possible by Board Multi-ID function), these logic "PQ1"(pysical type is N2) can be protected by the physically SSN1PQ1 in protection slot.
But it is not suggested to do like this. You better can insert SSN2PQ1 in protection slot, this board can protect both N2PQ1 and PQ1.