AT&T System 25 - Manual (Page 151)

INSTALLATION
Connection to TN763 Auxiliary Trunk CP (278A Adapter
Required)
A 278A Adapter is required to connect paging equipment to a TN763 Auxiliary
Trunk CP (Figure 2-56) when the following conditions
l Paging equipment is not FCC registered.
l Paging equipment requires a contact closure
Connect as shown in Figure 2-56, following the steps
1.
2.
3.
4.
Connect the CP to a 66-type block, using
Use kit-of-parts D-1 81524 (PEC 6251 1).
Note: The 66-block provides a 3-pair
e x i s t :
for proper operation.
below:
an A25D 25-pair cable.
interface to TN763
(see Appendix A of this manual for details).
Using 4-pair inside wiring cable,
66-type block to a 278A adapter.
CP Leads*
T
R
S Z
SZl
S
S 1
l T,R is the voice pair; SZ,SZ1 is
is the seizure acknowledge pair.
connect the following leads on the
278A Term.
T
R
B Z 1
G R D
B Y 1
B Y 2
the seizure request pair; and S,S1
Open the 278A adapter, and install a strap between terminals BZ2
and -V.
Move the yellow shorting plugs so that the following connections are
made (Figure 2-57).
A to B
E to F
G to H
D to C and J to K should be open.
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