Comtech EF Data CDM-Qx, Installation And Operation Manual

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CDM-Qx Satellite Modem Revision 6
External Connections MN/CDMQx.IOM
4.4.7 RS-530 Data Interface Connector
The Data connector is a 25-pin ‘D’ type female (DB-25F). This
connector conforms to the RS-530 pinout, which allows for
connection of different electrical standards, including EIA-422,
V.35, and EIA-232.
IMPORTANT
All data interfaces are duplex! They will only operate as duplex if a
Modulator and Demodulator are vertically grouped together as a modem.
In that case the data interface connector on the Demodulator switches to
duplex. This feature allows a single data interface connection to be used
for a modem instead of needing a “Y” cable. Otherwise, the data
interface for each module will only operate as simplex.
It is the responsibility of the user to provide the appropriate cables to
connect to this RS-530 connector.
Table 4-5. RS-530 Data Interface Connector Pin Assignments
Pin #
Generic Signal
Description
Direction
RS-422
RS- 530
LVDS
V.35 RS-232 Circuit #
2 TX Data A DTE to Modem SD A SD A BA 103
14 TX Data B DTE to Modem SD B SD B - 103
24 TX Clock A DTE to Modem TT A SCTE A DA 113
11 TX Clock B DTE to Modem TT B SCTE B - 113
15 INT TX Clock A Modem to DTE ST A SCT A DB 114
12 INT TX Clock B Modem to DTE ST B SCT B - 114
3 RX Data A Modem to DTE RD A RD A BB 104
16 RX Data B Modem to DTE RD B RD B - 104
17 RX Clock A Modem to DTE RT A SCR A DD 115
9 RX 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
(RS-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 RS-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 redundancy system.
3. ‘B’ signal lines are not used for RS-232 applications.
4. For X.21 operation, use the EIA-422 pins, but ignore RX Clock if the Modem is DTE, and ignore TX clocks if the Modem
is DCE.
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