APS-4C to SC-40C connections are done on the Class 2 terminal blocks on both units as follows.

APS-4C Pin        SC-40C Pin       Next SC-40C Pin
4———————4————————–4
5———————6————————–6
7———————5————————–X
X———————7————————–5

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Connection from APS-4C to SC-40C
Connection from SC-40C to SC-40C