Specifications

Appendix A Connector Wiring FOM-40 Installation and Operation Manual
A-2 V.24, V.35 and X.21 Interface Connectors
Table A-1. DTE Interface Signal Assignments (Cont.)
V.24 V.35 X.21 Description Signal
Function
DB-25
Standalone
and Card
Cage
DB-25
Card
Cage
34-Pin
Standalone
Pin Circuit
DB-25
Card
Cage
DB-15
Standalone
Pin Circuit
(Function)
Data Set
Ready
6 6 E DSR 107 A positive level from
FOM-40 when power is on,
and FOM-40 is (a) not in
digital loopback mode, or
(b) has not received a
remote loopback signal
from the remote unit.
Data
Terminal
Ready
20 20 H DTR 108 Not used
Carrier
Detect
8 8 F DCD 109 8
10
5 I(A)
12 I(B)
(Indication)
A positive level from
FOM-40, except when a
loss of the received signal is
detected or when Data Set
Ready is negative.
External
Transmit
Clock
24 19
16
U SCTE(A) 113
W SCTE(B) 113
24
11
7 (A)*
14 (B)*
A serial data rate clock
input from the data source.
Positive clock translations
must correspond to data
transmissions.
Transmit
Clock
15 14
10
Y SCT(A) 114
a SCT(B) 114
15
12
6 S(A)
13 S(B)
(Signal
Timing)
A transmit data rate clock
for use by an external data
source. Positive clock
translations correspond to
data translations.
Receive
Clock
17 23
22
V SCR(A) 115
X SCR(B) 115
A receive data rate clock
output used by an external
data sink. Positive clock
translations correspond to
data translations.
Local Analog
Loop
18 18 L and j A control signal input,
which, when on, sets
FOM-40 into local analog
loopback (V.54 Loop 3).
Remote
Digital Loop
21 21 N and h A control signal input
which, when on,
commands FOM-40 to
send a remote loopback
command (V.54 Loop 2) to
the remote FOM-40.
Test
Indicator
25 25 n and k A Control Signal output
from FOM-40; positive
during any test mode.