Watchdog (Wd); Fan Monitoring - Siemens Simatic box pc 627b Operating Instructions Manual

Functions

9.3 Watchdog (WD)

9.3 Watchdog (WD)
9.3
Function
The watchdog monitors the program execution and reports a program crash to the user by
means of various reactions.
The watchdog is idle when the PC is switched on or after a HW-RESET(cold restart), i.e., no
reaction of the WD is triggered.
WD reactions
If the WD is not triggered again within the set time (by driver or SOM program), the following
reactions are initiated:
Reaction
WD acknowledgement
Trigger a PC reset
SOM or DiagMonitor- software is activated
WD monitoring times TWD
The TWD are adjustable in increments of one second in a range from 3 to 255 seconds.
Note
If the watchdog time is changed after the watchdog was enabled (i.e., while the watchdog is
running), the watchdog is retriggered!
9.4

Fan monitoring

9.4
The function monitors operation of the enclosure and power supply fans. When a fan fails,
the following reactions are triggered:
Response
SOM or DiagMonitor software is activated
The temperature error is retained until the cause of the fan failure has been rectified and the
error is reset in one of the following ways:
• Acknowledgement of the error message by means of the SOM program
• Restart of the device
9-2
Option
None
Configurable
None
Option
None
Operating Instructions, Release 05/2006, A5E00362052-03
SIMATIC Box PC 627