CDM-600 Satellite Modem Revision 7
Connector Pinouts MN/CDM600.IOM
5–3
5.4 Data Interface Connector (P3B)

The Data Interface connector, a 25-pin D type female, 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 5-4 for pin assignments.

Table 5-4. Data Interface Connector Pin Assignments

Pin # Generic Signal
description Direction
EIA-422
EIA 530
LVDS
V.35 EIA-232 Circuit #
2 Transmit Data A DTE to Modem SD A SD A BA 103
14 Transmit Data B DTE to Modem SD B SD B - 103
24 Transmit Clock A DTE to Modem TT A SCTE A DA 113
11 Transmit Clock B DTE to Modem TT B SCTE B - 113
15 Internal Transmit
Clock A
Modem to DTE ST A SCT A DB 114
12 Internal Transmit
Clock B
Modem to DTE ST B SCT B - 114
3 Receive Data A Modem to DTE RD A RD A BB 104
16 Receive Data B Modem to DTE RD B RD B - 104
17 Receive Clock A Modem to DTE RT A SCR A DD 115
9 Receive Clock B Modem to DTE RT B SCR B - 115
8 Receiver Ready A Modem to DTE RR A RLSD * CF 109
10 Receiver Ready B Modem to DTE RR B - - 109
23 External Carrier Off
(EIA-232 ‘1' or TTL
‘low’ )
DTE to Modem - - - -
7 Signal Ground - SG SG AB 102
1 Shield - Shield FG AN 101
Notes:
1. Receiver Ready is an EIA-232 -level control signal on a V.35 interface.
2. DO NOT connect signals to pins which are not shown - these pins are reserved for use by the redundanc y
system.
3. ‘B’ signal lines are not used for EIA-232 applications.
4. For X.21 operation, use the EIA-422 pins, but ignore Rece ive Clock if the Modem is DTE, and ignore
Transmit clocks if the Modem is DCE.
5. For IDR operation using G.703, this primary interface becomes the 8 kbps EIA-422 overhead channel.