Comtech EF Data CDM-550T - Manual (Page 34)

CDM-550T Satellite Modem Revision 3
Rear Panel Connector Pinouts MN/CDM550T.IOM
5.2 Data Interface Connector, DB-25F
Table 5-1. Data Connector, 25-pin Type ‘D’ Female
Pin Generic Signal description Direction
RS-422/
RS-530
V.35 RS-232
Circuit
No.
1 Shield - Shield FG AN 101
2 Transmit Data A DTE to Modem SD A SD A BA 103
3 Receive Data A Modem to DTE RD A RD A BB 104
7 Signal Ground - SG SG AB 102
8 Receiver Ready A Modem to DTE RR A RLSD * CF 109
9 Receive Clock B Modem to DTE RT B SCR B - 115
10 Receiver Ready B Modem to DTE RR B - - 109
11 Transmit Clock B DTE to Modem TT B SCTE B - 113
12 Internal Transmit Clock B Modem to DTE ST B SCT B - 114
14 Transmit Data B DTE to Modem SD B SD B - 103
15 Internal Transmit Clock A Modem to DTE ST A SCT A DB 114
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
23
External Carrier Off
(RS-232 ‘1' or TTL ‘low’ )
DTE to Modem - - - -
24 Transmit Clock A DTE to Modem TT A SCTE A DA 113
NOTES:
•
Receiver ready is an RS-232-level control signal on a V.35 interface
•
DO NOT connect signals to pins which are not shown - these pins are reserved for use by the
redundancy system
•
‘B’ signal lines are not used for RS-232 applications
•
For X.21 operation, use the RS-422 pins, but ignore Receive Clock if the Modem is DTE, and ignore
Transmit clocks if the Modem is DCE
5–2