In 1-of-9 mode, the remote relay 'hot' wires (+12 or +24vdc) are
connected to terminals 1, 2, 3, 4, 5, 6, A, B, or C.

The common return wires can be connected to any of the 3 GROUND
connections on J2 or J4. All corresponding terminals on J2 and J4 are
common, this is done to accommodate wiring situations where there are
several remote relay locations.

The coil returns (labeled RETURNS ABCDEF) are only for the 1-of-36
configuration. They provide "switched ground" so that only the appropriate
set of remote relays will operate when a number relay is operated i.e. A1,
only the number 1 relay in the A group will operate. The difference between
ground and coil returns is that the coil returns are grounded only when the
corresponding letter relays (A-F) are operated.

Configuration of the DAS for 1-of-9 or 1-of-36 operation is set by
the position of internal DIP-switch S1-3 :
S1-3 ON = 1-of-9
S1-3 OFF = 1-of-36