Siemens SIMATIC Box PC 840 Manual page 151

Assignment for CPU Fan Supply, X41
Pin No.
1
2
3
Assignment for Main Fan Supply, X42
Pin No.
1
2
3
Connection for Backup Battery, X49
The battery for the standby supply to the CMOS RAM is connected to this
connection. A 3.6 V lithium battery with a capacity of 750 mAh is used.
Pin No.
1
2
SIMATIC Box PC 840 Manual
A5E00085984-04
Designation Description
GND Ground
+12V Switched power supply
CPU FAN_CLK Speed signal
Designation Description
GND Ground
+12V Switched power supply
PG1 FAN_CLK Speed signal
Designation Description
+ Positive pole
– Negative pole
Hardware Information
Input / Output
–
Output
Input
Input / Output
–
Output
Input
Input / Output
Input
–
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