34
Connecting Link Adapters and RS-422A Converters
Section 2-3
Block Diagram
The following diagram shows the internal block diagram of the NT-AL001 Link
Adapter. Refer to this diagram only when wiring custom cables or connecting
devices with special interfaces.
RS-422A/485 Cable Shield
Connections
When using RS-422A or RS-485 cables for long-distance communications, do
not ground the shield at both ends of the communications line because large
currents can flow through the shield due to the difference in potential at the
two grounding points. We recommend grounding the shield at one end, as
shown in the following diagram.
8
Data terminal ready
(shorted to DR internally)
ER
RS-232C Device
←
Link Adapter
9
Signal ground
SG
---
Pin
Signal name
Code
Signal direction
(RS-232C Device
⇔
Link Adapter)
SW1-6
R
R
D-SUB 9-pin
Case
+5 V
SG
SD
RD
RS
CS
DR
ER
6
9
2
3
4
5
7
8
POWER
Indicator
RS-232C
Dr/Rec
RS-422A/485 Dr/Rec
DC-DC
IS_5 V
IS_0 V
FG
1
2
3
4
6
5
7
8
SW1-5
SW1-4
SG
SDB
SDA
RDB
RDA
CSB
CSA
SW1-2
RS-422A Dr
SW1-3
RS-232C side
Fuse
Converter
Photocoupler
R
R
R
R
L
L
REG
RS-422A/485 side
8 terminal block
2-wire/
4-wire
Terminating
resistance
RS-232C
RS-232C
RS-232C
NT20
NT20
NT20
Host
Signal lines
NT-AL001
RS-422A/485
shield
Connect to the
terminal block's
FG terminal.
Summary of Contents for NT20
Page 1: ...Programmable Terminal Cat No V091 E1 01 NT20 USER S MANUAL ...
Page 2: ...NT series Programmable Terminal User s Manual Produced March 2007 ...
Page 3: ...iv ...
Page 5: ...vi ...
Page 9: ...x TABLE OF CONTENTS ...
Page 15: ...xvi ...
Page 21: ...xxii EC Directives 6 ...
Page 37: ...16 Before Operating Section 1 6 ...
Page 153: ...132 Transferring the Resource Data Section 3 11 ...
Page 185: ...164 Numeral Setting Section 4 8 ...
Page 267: ...246 Key to Programs Section 6 8 ...
Page 281: ...260 Specifications Appendix A ...
Page 285: ...264 Transporting and Storing PTs Appendix C ...
Page 303: ...282 Function Restrictions Depending on the Support Tool Appendix I ...
Page 307: ...286 Index ...
Page 309: ...288 Revision History ...