Terrestrial Data Connections; Data Interface Connector, Db-25F; Table 3-2. Data Interface Connector Pin Assignments - Comtech EF Data CDM-625 Installation And Operation Manual

CDM-625 Advanced Satellite Modem
Rear Panel Connector Pinouts
3.3

Terrestrial Data Connections

3.3.1

Data Interface Connector, DB-25F

Table 3-2. Data Interface Connector Pin Assignments

Generic Signal
Pin #
Description
2 Transmit Data A
14 Transmit Data B
24 Transmit Clock A
11 Transmit Clock B
Internal Transmit
15
Clock A
Internal Transmit
12
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
Notes:
1. When the rear-panel LED marked "1:N Active!" is OFF, 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 LED marked "1:N Active!" is ON, the signals shown highlighted are no longer available.
Furthermore, pins 6, 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 redundancy switch.
3. For X.21 operation, use the EIA-422 pins, but ignore Receive Clock if the Modem is DTE, and ignore Transmit
clocks if the Modem is DCE.
4.
For IDR operation using G.703, this primary interface becomes the 8 kbps EIA-422 overhead channel.
The Data Interface connector is a 25-pin, Type 'D' female interface that
conducts data input and output signals to and from the modem, and
connects to customer's terrestrial equipment, breakout panel, or
protection switch. Refer to Table 3-2 for pin assignments.
EIA-422
Direction
EIA 530
DTE to Modem SD A
DTE to Modem SD B
DTE to Modem TT A
DTE to Modem TT B
Modem to DTE ST A
Modem to DTE ST B
Modem to DTE RD A
Modem to DTE RD B
Modem to DTE RT A
Modem to DTE RT B
Modem to DTE RR A
Modem to DTE RR B
Modem to DTE CS A
Modem to DTE CS B
DTE to Modem RS A
DTE to Modem RS B
Modem to DTE DM A
Modem to DTE DM B
- SG
- Shield
3–4
MN-0000036 (Ref MN/CDM625.IOM)
V.35 HSSI
SD A SD A
SD B SD B
SCTE A TT A
SCTE B TT B
SCT A ST A
SCT B ST B
RD A RD A
RD B RD B
SCR A RT A
SCR B RT B
RLSD CA A
- CA B
CTS -
- -
RTS TA A
- TA B
DSR -
- -
SG SG
FG Shield
Revision 1
LVDS Circuit #
SD A 103
SD B 103
TT A 113
TT B 113
ST A 114
ST B 114
RD A 104
RD B 104
RT A 115
RT B 115
RR A 109
RR B 109
- 106
- 106
- 105
- 105
- -
- -
SG 102
Shield 101