Automatic control function programming manual ladder language

7.1 Introduction
Task Management
For further information concerning processing of the background tasks, see Section 2.1.2.3.
7.2 Start a Critical Section csbegin
Syntax
csbegin()
Operation
Inhibits pre-emption of the calling task by another %TS, %TH or %TF task.
Return code
Always OK
0
7.3 End a Critical Section csend
Syntax
csend()
Operation
Authorises pre-emption of the calling task by a higher priority task. This function cancels the effects of function
csbegin().
Return code
Always OK
0
7.4 Suspend a %TF task whtr
Syntax
whtr(n)
n: Number of real time clock cycles during which the %TF task is on
WAIT.
Operation
Changes the calling %TF task from EXECUTING state to WAITING state for n RTCs. At the end of this time, the %TF
task goes into READY state. n must be between 0 and 255, (equivalent to 0 to 5.1 secs).
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