Appendix C. IR- X.21B Interface Module

ASM-20Installation and Operation Manual

 

 

 

 

 

 

 

 

 

C.3

IR-X.21B Connectors

 

Figure C- shows the rear panel of a standalone ASM-20 with the IR-X.21B

interface module.

 

 

 

&$87,21￿)25&21,18('

D T E

 

 

 

 

 

3527(&7,21$*$,1675,6.2)

 

 

 

),5(￿5(3/$&(21/<:,7+6$0(

 

 

 

7<3($1'5$7,1*2))86(￿

 

 

 

 

X2 1

Line Connector

Figure C-2 ASM-20 Rear Panel with X.21 Connector

The ASM-20 modem rack version requires an additional adapter to connect between the DB-15 connector of the X.21 equipment to the DB-25 connector of the ASM-MN-214 modem rack. For this purpose, an optional DB-15 attachment CIA/X.21 can be ordered separately from RAD. The attachment connects to the ASM-MN-214 rear panel as shown in Figure 5-3for the CIA/V.35 attachment.

Pin Assignment

Table C-1shows the X.21 DB-15 pin assignment.

Table C-1 IR-X.21B DB-15 (RS-422) Connector Pin Assignment

Pin

ID

Function

 

 

 

1

Shield

Chassis connection

 

 

 

2

A

Transmit signal A

 

 

 

3

A

Control A

 

 

 

4

A

Receive A

 

 

 

5

A

Indication A

 

 

 

6

A

Signal timing A

 

 

 

7

A

External Timing

 

 

 

8

GND

Common

 

 

 

9

B

Transmit B

 

 

 

10

B

Control B

 

 

 

11

B

Receive B

 

 

 

12

B

Indication B

 

 

 

13

B

Signal Timing B

 

 

 

14

B

External Timing

 

 

 

C-2 IR-X.21B Interface Module

Page 59
Image 59
RAD Data comm ASM-20 Interface module $87,21 25&21,18, Table C-1 IR-X.21B DB-15 RS-422 Connector Pin Assignment