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5-1
Section
Connecting to the Host’s RS-422A/485 Port
90
Reference:
S
The RS-422A standard 1:N NT link method can be used only when the follow-
ing Boards/Units are installed:
CS1W-SCB41 Serial Communications Board in a CS-series CS1G/H(-H)
CJ1W-SCU41 Serial Communications Unit in a CJ-series CJ1G
Serial Communications Board in a C200HX/HG/HE(-Z)E
CQM1H-SCB41 Serial Communications Board in a CQM1H
S
The RS-422A high-speed 1:N NT link method can be used only when the fol-
lowing Boards/Units are installed:
CS1W-SCB41 Serial Communications Board in a CS-series CS1G/H(-H)
CJ1W-SCU41 Serial Communications Unit in a CJ-series CJ1G
Connecting the NT21s to the Link Adapters (RS-232C)
The RS-232C connections between the NT21s and Link Adapters in a 1:N con-
figuration are the same as the connection in a 1:1 configuration. Refer to Con-
necting the NT21 to the Link Adapter (RS-232C) on page 85 for details on the
RS-232C connections.
Connecting the Link Adapters between NT21s (RS-422A)
RS-422A
(Total length:
500 m max.)
NT21
Host
Link Adapter
(NT-AL001 or
NS-AL002)
Shield
NS-AL002
NT-AL001
Pin number
Abbreviation
F. Ground
SG
SDB
SDA
RDB
RDA
CSB
CSA
DIP Switch Settings
NT-AL001:
Pins 1 and 6 ON
Pins 2 to 5 OFF
(Turn ON pin 2 to enable the
terminator in the last Unit.)
NS-AL002:
Pin 1 ON
Pins 2 to 4 OFF
(Turn ON pin 4 to enable the
terminator in the last Unit.)
Link Adapter
RS-422A
terminal
block
NT-AL001
1
2
3
4
5
6
7
8
NS-AL002
1
---
3
7
2
6
---
---
Pin number
Abbreviation
F. Ground
SG
SDB
SDA
RDB
RDA
CSB
CSA
DIP Switch Settings
NT-AL001:
Pins 1 and 6 ON
Pins 2 to 5 OFF
(Turn ON pin 2 to enable the
terminator in the last Unit.)
NS-AL002:
Pin 1 ON
Pins 2 to 4 OFF
(Turn ON pin 4 to enable the
terminator in the last Unit.)
Link Adapter
RS-422A
connector
NT-AL001
1
2
3
4
5
6
7
8
NS-AL002
1
---
3
7
2
6
---
---
7
5
3
1
8
6
4
2
NS-AL002
NT-AL001
7
5
3
1
8
6
4
2
To avoid an FG ground loop, do not connect the functional ground of only one of
the Link Adapters to the shielding of the RS-422A cable.