<9. Advanced Engineering >
186
TI 34P02K35-02E May 31, 2017-00
9.1.10 Getting FCN-500, FCN-RTU Time
The following function blocks can be used in a control application to get the current
time of an FCN-500 or FCN-RTU .
PAS_GETTIME (get local time)
PAS_GETTIME2 (get current time in milliseconds or convert current time to
milliseconds)
The time returned by these two function blocks is the time when they are executed.
TIP
Although both PAS_GETTIME and PAS_GETTIME2 functions have “PAS” in their function names, they
are not included in PAS_POU but in the FCN/FCJ basic function blocks.
As such, the PAS_POU license is not required for using these functions, which can also be used in
applications using NPAS_POU.
● Selecting between PAS_GETTIME and PAS_GETTIME2
Both PAS_GETTIME and PAS_GETTIME2 function blocks return FCN-500 or FCN-
RTU time information but PAS_GETTIME2 can return time information in
milliseconds.
Moreover, PAS_GETTIME2 has all the functions of PAS_GETTIME and more so its
use is recommended.
● Programming Precautions
Some control applications require performing certain processing at a specific time of
the day. When programming this kind of application, observe the precaution
described below.
Example: To perform certain processing daily at 02:00 hours
This sample control application gets the current time using PAS_GETTIME or
PAS_GETTIME2, and executes certain processing when the returned time
matches a preset time.
If the preset time is 02:00:00 hours, this condition will be true for only one
second. During this second, PAS_GETTIME or PAS_GETTIME2 may fail to
return the current time if CPU load on the FCN-500 or FCN-RTU is heavy.
To avoid problems, do not compare the returned time against 02:00:00 hours but
rather check for change of time from 01:59 hours to 02:00 hours.
IMPORTANT
In duplex CPU configuration, the output value of this POU may be inconsistent.
When this output value is used in control logic, results of the left and right CPUs
may be inconsistent. Therefore, do not use the output value of this POU in logic for
duplex CPU systems.
Summary of Contents for STARDOM FCN-500
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