Omron NT31 Operation Manuals page 154

Connecting to the Host's RS-422A/485 Port
Connecting between NT31/NT31C Units
1
13
NT31/NT31C
RS-485
:
NT31/NT31C side
14
Abbreviation
FG
−
RS-232C/
SD
422A/485
RD
connector
RS
CS
−
SG
−
TRM
RDB (+)
SDB (+)
−
−
−
SDA (−)
RDA (−)
25
−
−
RSB (+)
RSA (−)
−
(25-pin type)
* Make the connection between pin numbers 9 and 10 at the NT31/NT31C at the end
of the RS-485 cable (marked "
In order to avoid an FG ground loop, do not connect the functional ground of the
NT31/NT31C to the shielding of the RS-422A cable.
Pin number Pin number
Shielding wire
Connector Connector
hood hood
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
:
9 9
10 10
11 11
12 12
13 13
14 14
15 15
16 16
− −
23 23
24 24
25 25
Next PT
" in the figure above) only.
:
Section 5-2
Host
NT31/NT31C side
1
Abbreviation
FG
−
RS-232C/
SD
422A/485
RD
connector
RS
CS
−
SG
−
TRM
RDB (+)
SDB (+)
−
−
−
SDA (−)
RDA (−)
13
−
−
RSB (+)
RSA (−)
−
(25-pin type)
14
25
143