RS-449 Interface

The EIA RS-449 standard specifies the functional and mechanical characteristics of
the interconnection between Data Terminal Equipment (DTE) and complying
to EIA electrical interface standards RS-422 and RS-423.

Pin EIA
CKT
Description From
DCE
To
DCE
A B
1
2
 
SI
Shield
Signaling Rate Indicator

*C
 
4
5
22
23
SD
ST
Send Data
Send Timing

*T
*D

6
7
24
25
RD
RS
Receive Data
Request to Send
*D


*C
8
9
26
27
RT
CS
Receive Timing
Clear to Send

*T

*C
10
11

29
LL
DM
Local Loopback
Data Mode

*C
*C

12
13
30
31
TR
RR
Terminal Ready
Receiver Ready

*C
*C

14
15
  RL
IC
Remote Loopback
Incoming Call

*C
*C

16
17

35
SR
TT
Signaling Rate Selector
Incoming Call
  *C
*T
18
19
  TM
SG
Test Mode
Signal Ground
*C

 
20
28
  RC
IS
Receive Common
Terminal in Service
 
*C
32
33
  SS
SQ
Select Standby
Signal Quality

*C
*C

34
36
37
  NS
SB
SC
New Signal
Standby Indicator
Send Common
*C



*C

Signal Type: D = Data, C = Control, T = Timing
Note: On the DB37 connector that is commonly used for RS449; Pins 3 and 21 are undfined
B = Return


Please make a selection.