CTC Union ETU-01A User Manual

Appendix A. I/F Specifications
119
November 2001
A.2 X.21 User Data Channel Connector
When the ETU-01A is ordered with an X.21 interface, the
physical interface is a 15-pin female D-type connector wired in
accordance with Table A-3.
SIGNAL
FUNCTION
PIN
CIRCUIT
DIRECTION DESCRIPTION
Protective
Ground
1 Shield ↔↔
Chassis ground.
May be isolated from Signal
Ground.
Signal
Ground
8 G ↔↔ Common signal ground.
Transmitte
d
Data
2
9
T(A)
T(B)
To ETU-01A
Serial digital data from DTE.
Received
Data
4
11
R(A)
R(B)
Fm ETU-01A
Serial digital data at the output of
the ETU-01A receiver.
Request to
Sent
3
10
C(A)
C(B)
To ETU-01A
A ON signal to the ETU-01A when
data transmission is desired.
Data
Carrier
Detect
5
12
I(A)
I(B)
Fm ETU-01A
Constantly ON, except when a loss
of the received carrier signal is
detected.
Signal
Timing
6
13
S(A)
S(B)
Fm ETU-01A
A transmit data rate clock for use
by an external data source.
External
Transmit
clock
7
14
B(A)
B(B)
To ETU-01A
A serial data rate clock input from
the data source.
-- 15 -- -- --
Table A-3 X.21 user data channel connector pin allocation

CTC Union ETU-01A Specifications

General

Brand	CTC Union
Model	ETU-01A
Category	Control Unit
Language	English