363-206-295
Shelf Descriptions and Configurations
Issue 1
December 1997
3-5
Four 12-inch slots, designated MAIN, are for the main OC-12 OLIU circuit packs.
These circuit packs are arranged in two service and protection pairs designated
main A and main B. Main A slots 1 and 2(P) must be equipped with 177C
apparatus blanks (APPBLK) except when the shelf is used as an OC-12
Regenerator shelf.
Two 12-inch slots, designated TSI, are for two time slot interchange (TSI) circuit
packs.
Two 4-inch slots, designated TG, are for two timing generator packs (TGS/TG3),
service and protection.
One 12-inch slot, designated AUXCTL, is for the overhead controller (OHCTL)
circuit pack.
Eight 8-inch slots, designated FN, are for function unit circuit packs. These slots
are divided into four groups designated A, B, C, and D. The FN slots can be
equipped interchangeably by group, with service and protection.
One 8-inch slot, designated SYSCTL, is for the main controller circuit pack
(SYSCTL).
The user panel mounted on the far right side of the shelf consists of the following:
■
Two
−
48 volt fuses (10A)
■
Four alarm LEDs
■
ACO/TEST pushbutton control
■
Five status LEDs
■
CIT port
■
ESD jack.
Accidental insertion of same-size circuit packs in incorrect slots is prevented
through circuit pack keying. The key mechanism is located on the faceplate latch,
with an interference mechanism on the shelf.
