Adding A Modem Expansion Board - Honeywell Mercury User Manual

Page 24
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Adding a Modem Expansion Board

3. Remove and save the (2) screws from the upper corners and the
screw and cable clip from the lower right corner of the modem circuit
board. Replace each with (1) 20-7285 5/8" M-F standoff, provided in
kit.
4. Install the expansion board/mounting plate assembly (pro-
vided in kit) on the standoffs using the (3) screws previously removed,
attaching the cable clip in the lower right corner.
5. Attach the expansion board cable to the expansion board by
routing the cable around the left side of the expansion board mounting
plate and plugging the keyed connector (with the vinyl pull-tab) into
the socket located on the upper left edge of the expansion board.
6. Connect the ground lug located in the lower right corner of the
expansion board to the ground lug on the modem board, which should
in turn be connected to earth ground. Later units contain a green screw
attached to the case for use as a ground terminal.
When making wiring connections to the modem board or
7.
expansion board, wire routing is important, especially with re-
spect to the signal and phone connections. Phone wiring should
not lay across wiring to ports A-D, as crosstalk may occur. Later
units contain a modular phone jack to terminate external phone wiring.
Use cable tie-downs and clips provided in the unit as necessary to
provide separation when routing wiring to the boards through appro-
priately labeled Hubbell fittings.
8. After all wiring is complete, reinstall the battery plate and
tighten the mounting screws. Reconnect all batteries.