Using an RS-232C/RS-422A Adapter

Appendix C

Block Diagram

A diagram showing the internal blocks of the Adapter is shown below. Refer to this diagram when making cables yourself, or when connecting devices with special interfaces.

RS-232C side

D-SUB 9P CASE

 

 

 

RS-422A/485 side

 

POWER

RS-422A/485 Dr/Rec

8P terminal block

 

 

R

LED

DC-DC Convertor

 

+5 V

6 Fuse

 

 

IS_5 V

1

FG

 

 

 

L L REG

 

 

SG

9

 

 

 

IS_0 V

2

SG

 

 

 

 

 

 

 

 

 

RS-232C

Photocoupler

R R R

 

3

SDB

 

 

 

Dr/Rec

 

 

 

4

 

 

 

SDA

 

 

 

 

 

RD 3

 

SW1-6

2-wire type/

 

4-wire type

 

 

R

SW1-3

SW1-4

SD

2

SW1-5

 

5

RDB

 

RS 4

CS 5 DR 7

ER 8

 

 

6

RDA

 

 

 

Terminator

R

SW1-2

 

 

 

 

 

 

RS-422A Dr

7 CSB

8 CSA

264

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Image 281
Omron NT631C manual Block Diagram