Omron Programmable Terminals NT31 NT31C Setup Manual page 105

Connecting to the Host's RS-232C Port
Connecting an
NT31/NT31C and
NT-AL001 (RS-485)
1
13 25
94
The relay terminal board is not included in the figure below. Insert a relay termi-
nal board so as to achieve the wiring configuration indicated below.
NT31/NT31C
RS-485
14
NT31/NT31C side
Abbreviation
FG
−
RS-232C/ SD
422A/485
RD
connector
RS
CS
−
SG
−
TRM
RDB (+)
SDB (+)
−
−
−
SDA (−)
RDA (−)
−
−
RSB (+)
RSA (−)
−
(25-pin type)
In order to avoid an FG ground loop, do not make the connections between the
functional ground of the NT-AL001 and the shielding.
Host
NT-AL001
Pin number
Shielding wire
Connector
hood
1
2
3
4
5
6
7
8
9
Pin number
10 6
11
5
12
4
13
3
14
1
15
16
−
23
24
25
Next PT
Section
7
5
3
1
NT-AL001 side
Abbreviation
RDA
RS-422A
RDB
terminal
SDA
block
SDB
Functional
ground
5-1
8
6
4
2