Siemens SIMATIC Box PC 820 Manual page 117

3.3 Connector Assignment of Keyboard Controller
Figure 3-1
Connector for External Keyboard
Pin
1
2
3
4
Connector for Keyboard Port on CPU
Pin
1
2
3
4
5
Siemens Distributor
Box PC 820 / PC FI45 V2, Manual
A5E00051531-03
Location of the Plug Connectors on the Controller Board
Description
CLOCK
+5 V
GND
DATA
Description
GND
+5 V
CLOCK
DATA
unassigned
Keyboard Controller (PC FI45 V2)
4-pin plug connector: ST1A/ST1B
1 2 3 4
ST1
5-pin plug connector: ST2
1 2 3 4
ST2
5
3-11