CDM-Qx Satellite Modem

Revision 5

External Connections

MN/CDMQx.IOM

4.4.7RS-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.

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 IMPORTANT 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

DTE to Modem

-

-

-

-

(RS-232 ‘1' or TTL ‘low’ )

 

 

 

 

 

 

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.

4–10

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Mocomtech CDM-QX 7 RS-530 Data Interface Connector, Pin # Generic Signal Description Direction RS-422 RS, Lvds