8.3 SCM – System Control Module Details
The SCM, or System Control Module, is made up of a control board and a core module, which is the
brains of the system. Connected to the SCM board is the Rack Control Interface described earlier in
this manual. Together, they plug into the Dimmer Control Card, which plugs into the Backplane. All
racks, regardless of size, use the same SCM module. Jumpers JP1 & JP2, test points TP6, 7 & 8, and
DIP Switch SW1 are illustrated and explained in the sections that follow.
8.3.1 Ride-Thru Disable
Ride-thru can be disabled by shunting JP1 on the SCM circuit board shown in Figure 19 below. This
may be useful for servicing the system and not having to wait for the ride-thru power to dissipate.
However, with ride-thru disabled, any changes to the system will not be stored to the MRAM on power
loss, so it must be done manually before shutting down the system.
There are two LED indicators on the SCM printed circuit board. LED1, when lit, indicates that the
super capacitors are being charged. LED1 will go out once the super capacitors are within 7.5% of full
charge. LED2 indicates that 3.3V DC power is present on the board and is applied to the main
processor code module.
Figure 19: Main System Control Module (SCM)
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