Rain Bird MDC2, Instructions Manual, Page: 20 / 124

Installation,
continued
14
Installing Program and Expansion
Modules
The MDC2 Controller uses a program
module that controls 50 (decoder) outputs. The
controller also supports up to three expansion
modules (MDC/M50D), each controlling an
additional 50 outputs. So, by adding expansion
modules, you can configure the MDC2 Controller
to control 50, 100, 150, or 200 outputs. 200 is the
maximum number of outputs the controller can
manage in any combination over one, two or three
separate two-wire communications lines.
Warning! When working with any program or
expansion module, always use a grounding
strap to avoid electrostatic discharge, which can
damage the modules .
Warning! Always turn off the controller before
you add or remove any module .
To add or replace a program or expansion module,
1. Use a Phillips head screwdriver to remove the
two screws and lock washers holding the guide
rail. Be careful not to lose the lock washers.
2. To remove a worn out module, grasp it by its tab
and wiggle it back and forth while pulling up.
3. Hold the new module by its tab, so the back of
the module faces the top of the cabinet.
4. Firmly plug a 10-pin expansion module into one
of the three corresponding sockets on the circuit
board. The program module is larger and fits
only in one socket.
Warning! When plugging a program or expansion
module into an MDC socket, please note its
orientation . Make sure the back of the module’s
mini circuit board is facing the top of the cabinet
and not the display screen . Plugging the modules
in backwards will not damage the controller, but
the controller will not work properly .
5. Once you install the modules, replace the
guide rail.