Svcreq 29: Read Elapsed Power Down Time; 1Output Parameter Block For Svcreq 29; 2Example Of Svcreq 29 - GE VersaMax PLC User Manual

11.21 SVCREQ 29: Read Elapsed Power Down Time

%I0251
SVC_
REQ
CONST
FNC
00029
%R0050
PARM
The Service Request Function
For public disclosure
Use SVCREQ 29 to read the amount of time elapsed between the last power-down and
the most recent powerup. If the watchdog timer expired before power-down, the PLC is
not able to calculate the power down elapsed time, so the time is set to 0.
The SVCREQ output is always ON.
11.21.1 Output Parameter Block for SVCREQ 29
This function has an output parameter block only. The parameter block has a length of 3
words.
Power-Down Elapsed Seconds (low order)
address
Power-Down Elapsed Seconds (high order)
address + 1
zero
address + 2
The first two words are the power-down elapsed time in seconds. The last word is always
0.
11.21.2 Example of SVCREQ 29
In the example, when input %I0251 is ON, the Elapsed Power-Down Time is placed into
the parameter block that starts at %R0050. The output coil (%Q0001) is turned on.
%Q0001
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