B-2
Cabling Specifications
Table B-2
DB25 RS-232 interface connector pinout
P i n N u m b e r
S i g n a l
D i r e c t i o n
D e s c r i p t io n
1
Shield
Chassis
ground
2
TX Out
Transmit
data
3
RX In Receive
data
4
RTS
Out
Request to send
5
CTS
In
Clear to send
6
DSR
In
Data set ready
7
GND
Signal common, connected to chassis ground
8
RLSD
In
Receive line signal detect
9
N.C.
No
connection
10
N.C.
No
connection
11
N.C.
No
connection
12
N.C.
No
connection
13
N.C.
No
connection
14
N.C.
No
connection
15
TXCLK
In
Transmit signal timing clock
16
N.C.
No
connection
17
RXCLK
In
Receiver signal timing clock
18
N.C.
No
connection
19
N.C.
No
connection
20
DTR
Out
Data terminal ready
21
RL
In
Signal quality detect (remote loopback)
22
RI In Ring
indicator
23
RS In Rate
selector
24
TXCLK Out
Transmit
clock
25
TM In Test
mode
The OM 1000 can either source or sink the transmit clock; this is determined by a configuration
selection. Sinking the clock is needed when sending data through a modem through a network
T1 line. In this case, the modem sources a clock that is locked to the network. The OM 1000
sinks the clock and sources data to the modem to be sent to the network.
OM 1000 Installation and Operation Manual
