SM500A—Automatic Switching System
Black Box Corporation
21
990-000-0001-E8
NOTE: The yellow LED, labeled “ENBL”, is illuminated to indicate that the “SYSTEM
GANG” function is active. To perform any local switching functions, the key-operated
switch must be in the ENABLE position.
3. Remote system gang switching via contact closure
—JP1 to JP5 in position 2-3.
This
card has an additional capability of performing system gang switching activated by an
external control voltage. This functionality is available through the “CONTACT
CLOSURE SWITCHING” port. The controlling voltage can be supplied from an RS232
control lead or any other source switched b12v and -12v or from an external
relay or switch contact using +12v and -12v available at the “CONTACT CLOSURE
SWITCHING” connector through a 1K ohm resistor. Switching to “A” re12v.
Switching to “B” requires -12v (refer to figure 3.5). This function can be extended to the
entire system by interconnecting all the Power Supply/Control Cards using RJ-11 cables
at the “GANG IN/GANG OUT” ports.
NOTE: A card with this configuration must first be in the interconnecting chain.
NOTE: The key-operated switch position on all chassis has no effect on the remote system
gang switching function.
Figure 3.3. Jumper settings on Power Supply/Control Card
