Serial/Industrial Interface Kit Installation Instructions 23
Chapter 3 — Serial Interface
Connector Confi guration (RS-422 Isolated on "uart2:", "uart3:", or
"uart4:")
DB-9 socket Signal Meaning
1 External +5VDC max 500 mA (automatic switch-
off at overload, short-circuit protected) provided
strap is fi tted on J2:A which spoils the galvanical
isolation
2 +TXD +Transmit data
3 +RXD +Receive data
4–
5 GNDE Ground
6-
7 -RXD -Receive data
8 -TXD -Transmit data
9–
RS-422 socket as seen from the outside.
4
5
3
2
1
8
9
7
6
+TXD
+5V (0.5 A)
if GND strap
fitted
+RXD
GNDE
-RXD
-TXD