If Connections; Data Interface Connector, Db-25F; Table 3-2. Data Interface Connector Pin Assignments - Comtech EF Data CDM-570 Installation And Operation Manual

CDM-570/570L Satellite Modem with Optional IP Module
Rear Panel Connectors and Pinouts
3.3

IF Connections

3.3.1 Data Interface Connector, DB-25F

and EIA-232. A shielded DB-25F connector provides a very solid solution to EMC problems,
unlike the sometimes-used V.35 Winchester connector.
Generic Signal
Pin #
Description
2 Transmit Data A
14 Transmit Data B
24 Transmit Clock A
11 Transmit Clock B
15 Internal Tx Clock A
12 Internal Tx Clock B
3 Receive Data A
16 Receive Data B
17 Receive Clock A
9 Receive Clock B
8 Receiver Ready A
10 Receiver Ready B
5 Clear to Send A *
13 Clear to Send B *
4 Request to Send A *
19 Request to Send B *
6 Data Set Ready A *
22 Data Set Ready B *
7 Signal Ground
1 Shield
1. When the rear-panel switch marked "1:N Switch" is in the OFF position, all of the signals shown
above are available and functional. In addition, pins not shown are not connected, and therefore no
damage will occur if other signals are connected to the additional pins.
2. When the rear-panel switch marked "1:N Switch" is in the ON position, the highlighted signals, plus
pins 18, 20, 21, 22, 23 and 25 are reserved for use by the 1:N system. DO NOT connect signals to
any of these pins in this mode. Certain pins have DC voltages present that may damage equipment
other than a Comtech EF Data redundancy switch.
For X.21 operation, use the EIA-422 pins, but ignore Receive Clock if the Modem is DTE, and ignore
3.
Transmit Clocks if the Modem is DCE.
The 25-pin 'D' type female (DB-25F) Data Interface connector
conducts data input and output breakout panel, or protection switch.
This connector conforms to the EIA-530 pinout, which allows for
connection of different electrical standards, including EIA-422, V.35,
THE MODEM IS ALWAYS ASSUMED TO BE DCE

Table 3-2. Data Interface Connector Pin Assignments

Direction
DTE to Modem
DTE to Modem
DTE to Modem
DTE to Modem
Modem to DTE
Modem to DTE
Modem to DTE
Modem to DTE
Modem to DTE
Modem to DTE
Modem to DTE
Modem to DTE
Modem to DTE
Modem to DTE
DTE to Modem
DTE to Modem
Modem to DTE
Modem to DTE
-
-
EIA-422
V.35
EIA-530
SD A SD A
SD B SD B
TT A SCTE A
TT B SCTE B
ST A SCT A
ST B SCT B
RD A RD A
RD B RD B
RT A SCR A
RT B SCR B
RR A RLSD
RR B -
CS A CTS
CS B -
RS A RTS
RS B -
DM A DSR
DM B -
SG SG
Shield FG
3–4
Revision 12
MN/CDM570L.IOM
EIA-232 Circuit #
BA 103
- 103
DA 113
- 113
DB 114
- 114
BB 104
- 104
DD 115
- 115
CF 109
- 109
CB 106
- 106
CA 105
- 105
CC 107
- 107
AB 102
AN 101