APPENDIX A: FXS Voice/Fax Interface Module
59
There are two connectors on the back panel of the
FXS interface card: J2 and TB1 (see Figure A-2). J2,
labeled “FXS,” is an RJ-11 modular connector used
in most FXS-type applications. TB1 is an 4-pin
terminal block that connects to a punch block.
Both J2 and TB1 are shielded by a protective cover.
Connectors J2 and TB1 terminate the Tip (T)
and Ring (R) leads in parallel, so that pins 2 and 3
of J2 are connected, respectively, to pins 1 and 2 of
TB1 (see Figure A-3).
In most applications, use a modular cable
(supplied) to connect the voice/fax channel to
telephone equipment. Connect one end of the
cable to the FXS connector on the voice/fax
interface card. Connect the other end to the
telephone equipment.
If you are connecting to a punch block, use the
terminal block (TB1). Use a cable with bare-wire
leads (not included) to connect the terminal block
and the punch block. The terminal block is fitted
with a female plug that serves as a receptacle for the
individual cable leads.
CAUTION!
Wiring to the trunk terminal block must
4
TB1
J2
FXS
3
2
1
SG —
R
T
SG —
R
T
Legend:
T
R
—
SG
=
=
=
=
Tip
Ring
No Connection
Signal Ground
Figure A-2. Connectors on the Back Panel of the FXS Interface Module.
4
TB1
J2
FXS
3
2
1
SG —
R
T
SG —
R
T
Legend:
T
R
—
SG
=
=
=
=
Tip
Ring
No Connection
Signal Ground
Figure A-3. Wiring of the Connectors on the Back Panele.