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Serial Pinout Diagrams

 
RS449 Pinouts

General
The RS449 interface is a generic connector specification. It's not an actual interface. The connector pinning was originally designed to support RS422 for balanced signals, and RS423 for the unbalanced signals. And should have been the succesor of RS232.

Sub-D37M

Sub-D37F

Male

Female

 

Pin

Signal

Abbr.

DTE

DCE

1

Shield

 

 

 

2

Signal Rate Indicator

S

Out

In

3

Unassigned

4

Send Data (A)

SD-

Out

In

5

Send Timing (A)

ST-

In

Out

6

Receive Data (A)

RD-

In

Out

7

Request To Send (A)

RS-

Out

In

8

Receive Timing (A)

RT-

In

Out

9

Clear To Send (A)

CS-

In

Out

10

Local Loopback

LL

Out

In

11

Data Mode (A)

DM-

In

Out

12

Terminal Ready (A)

TR-

Out

In

13

Receiver Ready (A)

RR-

In

Out

14

Remote Loopback

RL

Out

In

15

Incoming Call

IC

In

Out

16

Signal Freq./Sig. Rate Select.

SF/SR+

In/Out

Out/In

17

Terminal Timing (A)

TT-

Out

In

18

Test Mode (A)

TM-

In

Out

19

Signal Ground

SG

 

 

20

Receive Common

RC

 

 

21

Unassigned

22

Send Data (B)

SD+

Out

In

23

Send Timing (B)

ST+

In

Out

24

Receive Data (B)

RD+

In

Out

25

Request To Send (B)

RS+

Out

In

26

Receive Timing (B)

RT+

In

Out

27

Clear To Send (B)

CS+

In

Out

28

Terminal In Service

IS

Out

In

29

Data Mode (B)

DM+

In

Out

30

Terminal Ready (B)

TR+

Out

In

31

Receiver Ready (B)

RR+

In

Out

32

Select Standby

SS

In

Out

33

Signal Quality

SQ

In

Out

34

New Signal

NS

Out

In

35

Terminal Timing (B)

TT+

Out

In

36

Standby Indicator

SB

In

Out

37

Send Common

SC

 

 

 

Sub-D9M

Sub-D9F

Male

Female

 

Pin

Signal

Abbr.

DTE

DCE

1

Shield

 

 

 

2

Secondary Receiver Ready

SSR

 

 

3

Secondary Send Data

SSD

 

 

4

Secondary Receive Data

SRD

 

 

5

Signal Ground

SG

 

 

6

Receive Common

RC

 

 

7

Secondary Request To Send

SRS

 

 

8

Secondary Clear To Send

SCS

 

 

9

Send Common

SC

 

 

 

Functional description
Since RS449 is only a newer version of RS232 we will only describe the new signals.

Descripti on

Circuit

Function

Shield Ground

AA

Also known as protective ground. This is the chassis ground connection between DTE and DCE.

Signal Ground

AB

The reference ground between a DTE and a DCE. Has the value 0 Vdc.

Transmitt ed Data

BA

Data send by the DTE.

Received Data

BB

Data received by the DTE.

Request To Send

CA

Originated by the DTE to initiate transmission by the DCE.

Clear To Send

CB

Send by the DCE as a reply on the RTS after a delay in ms, which gives the DCEs enough time to energize their circuits and synchronize on basic modulation patterns.

DCE Ready

CC

Known as DSR. Originated by the DCE indicating that it is basically operating (power on, and in functional mode).

DTE Ready

CD

Known as DTR. Originated by the DTE to instruct the DCE to setup a connection. Actually it means that the DTE is up and running and ready to communicate.

Ring Indicator

CE

A signal from the DCE to the DTE that there is an incomming call (telephone is ringing). Only used on switched circuit connections.

Received Line Signal Detector

CF

Known as DCD. A signal send from DCE to its DTE to indicate that it has received a basic carrier signal from a (remote) DCE.

Data Signal Rate Select
(DTE/DC E Source>

CH/CI

A control signal that can be used to change the transmission speed.

Transmit Signal Element Timing
(DTE Source)

DA

Timing signals used by the DTE for transmission, where the clock is originated by the DTE and the DCE is the slave.

Transmitt er Signal Element Timing
(DCE Source)

DB

Timing signals used by the DTE for transmission.

Receiver Signal Element Timing
(DCE Source)

DD

Timing signals used by the DTE when receiving data.

terminal In Service

IS

Signal that indicates that the DTE is available for operation

New Signal

NS

A control signal from the DTE to the DCE. It instructs the DCE to rapidly get ready to receive a new analog signal. It helps master-station modems rapidly synchronize on a new modem at a tributary station in multipoint circuits

Receive Common

RC

A signal return for receiver circuit reference

Local Loopback / Quality Detector

LL

A control signal from the DTE to the DCE that causes the analog transmision output to be connected to the analog receiver input.

Remote Loopback

RL

Signal from the DTE to the DCE. The local DCE then signals the remote DCE to loopback the analog signal and thus causing a line loopback.

Standby Indicator

SB

Signal from the DCE to indicate if it is uses the normal communication or standby channel

Send Common

SC

A return signal for transmitter circuit reference

Select Frequenc y

SF

A signal from the DTE to tell the DCE which of the two analog carrier frequencies should be used.

Select Standby

SS

A signal from DTE to DCE, to switch between normal communication or standby channel.

Test Mode

TM

A signal from the DCE to the DTE that it is in test-mode and can't send any data.

Reserved for Testing

 

 

The secondary signals are used on some DCE's. Those units have the possibility to transmit and/or receive on a secondary channel. Those secondary channels are mostly of a lower speed than the normal ones and are mainly used for administrative functions.