SM500A—Automatic Switching System
Black Box Corporation
11
990-000-0001-E8
Figure 2.2. Rear view of SM500A chassis with cards inserted. Cards will vary according to application.
Slots 1-16 reserved for Switching Interface Cards. Slot 17 reserved for Power Supply/Control Card or
Advanced Control Card.
2.2 Control Cards
A Power Supply/Control Card or Advanced Control Card (figure 2.3) must be inserted into
slot 17 of the SM500A chassis. This card provides power and control to one chassis. Two
types of cards are available—one using 12VAC that can be also used with one or two Power
Modules if power redundancy is required or with the AC Redundant Power Supply; the other
type is used with -48VDC.
Model
Description
SM531-C
Power Supply/Control Card, 12VAC. Three types of control configuration are
available for this card, depending on one of the following applications in
which the SM500A chassis is used:
1. Chassis gang switching.
A toggle switch on the SM500A chassis front
panel, labeled “GANG”, provides the capability to perform gang switching on
chassis level. To perform local switching functions, the key-operated switch
on the chassis must be in the ENABLE position.
2. System gang switching.
By pressing and holding the “SYSTEM GANG”
pushbutton while toggling the “GANG” switch, switching is extended to the
entire system. All Power Supply/Control Cards must be interconnected via
RJ-11 cables using “GANG IN/GANG OUT” ports to perform system gang
switching. To perform local switching functions, the key-operated switch on
the
initiating
chassis must be in the ENABLE position. This overrides the
key-operated switch positions on the remaining interconnected chassis.
