COMSPHERE 3900 Series Modems
C-2 September 1998 3910-A2-GN32-40
EIA-232-D Pin Assignments
Table C-1 lists the EIA-232-D pin assignments for the modem.
Table C-1
EIA-232-D Pin Assignments
Pin Name EIA
Circuit CCITT Signal
Source Circuit Function
1—AA 101 —Shield
2 TXD BA 103 DTE Transmit Data
3 RXD BB 104 DCE Receive Data
4RTS CA 105 DTE Request-to-Send
5 CTS CB 106 DCE Clear-to-Send
6 DSR CC 107 DCE Data Set Ready
7 SG AB 102 —Signal Ground
8 LSD CF 109 DCE Line Signal Detect
9 +12V — — — Reserved for test purposes (may be used to drive
one RS-232 load)
10 –12V — — — Reserved for test purposes (may be used to drive
one RS-232 load)
11 — — — — Unassigned
12 CT112 CI 11 2 DCE Data Signal Rate Select
13 — — — — Reserved for future function
14 — — — — Reserved for future function
15 TXC DB 114 DCE Transmit Clock
16 — — — — Reserved for future function
17 RXC DD 115 DCE Receive Clock
18 CT141 LL 141 DTE Local Loopback
20 DTR CD 108 DTE Data Terminal Ready
21 CT140 RL 140 DTE Remote Loopback
22 RI CE 125 DCE Ring Indicator
23 CT111 CH 111 DTE Data Rate Selector
24 XTXC DA 113 DTE External Clock
25 TEST TM 142 DCE Test Mode