19
SHM-768K
Table 3-1. Interface Signal List (Female Connectors) Pins and
Standard Signal Names (continued).
V.35
EIA-530
X.21
Signal
DB25
34-Pin
DB25
DB25
DB15
Description
Function
Frame Standalone
Standalone
Frame
Standalone
Pin Circuit
Pin Circuit
Pin Circuit/
(Function)
External
19
U SCTE(A) 113 24 DA(A)
24
7 (A)
A serial data
Transmit
16
W SCTE(B) 113 11 DA(B)
11
14 (B)
rate clock input
Clock
from the data
source. Positive
clock transitions
must corre-
spond to data
transitions.
Transmit
14
Y SCT(A) 114
15 DB(A)
15
6 S(A)
A transmit data
Clock
10
a SCT(B) 114
12 DB(B)
12
13 S(B)
rate clock for
(Signal
use by an
Timing)
external data
source. Positive
clock transitions
correspond to
data transitions.
Receive
22
X SCR(B) 115
17 DD(A)
A receive data
Clock
23
V SCR(A) 115
9 DD(B)
rate clock
output for use
by external
data sink.
Positive clock
transitions
correspond to
data transitions.
Local
18
j
18 LL
A control signal
Analog
input: when on,
Loop
commands the
SHM into Local
Analog Loop-
back (V.54 Loop
3).
