Omron NT31 - Page 148

137
Connecting to the Host’s RS-422A/485 Port
Section 5-2
 Wiring for a Memory Link connection
Prepare the adapter cable while referring to the following diagram.
1
14
13 25
NT31/NT31C side
Shielding wire
(25-pin type)
Abbreviation
FG
−
SD
RD
RS
CS
−
SG
−
TRM
RDB (+)
SDB (+)
−
−
−
SDA (−)
RDA (−)
−
−
RSB (+)
RSA (−)
−
Pin number
Connector
hood
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
−
23
24
25
RS-232C/
422A/485
connector
Host side
RS-422A
connector
Abbreviation
Connecto
hood
SDA
SDB
RS
CS
ROA
ROB
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.