Automatic control function programming manual ladder language

13.1 General Description of the Timer Function
Timer Function
The timer function is available only on NUM 1060 series I and NUM 1060 series II multicard systems.
The automatic control function provides the user with two timers, A and B. They each consist of an 8-bit downcounter
capable of generating a pulse each time the contents are changed. The downcounter is then immediately reloaded
with a programmed value saved in the timer data register.
For further details on the wiring of these inputs, refer to the «Installation and Commissioning Manual».
13.2 Use of Timer A
13.2.1 Timeout Mode
In timeout mode, the frequency of the internal clock (2.4576 MHz) is divided by the programmable predivider which
supplies pulses to the downcounter.
INTERNAL
CLOCK
(2.4576 MHz)
Predivider
Downcounter
Timer A IT
13.3 Associate a %TH Task with a Timer thtimer
Syntax
thtimer(thno, timerno, nbmillisec)
thno: %TH task number.
timerno: Timer number (0 or 1).
nbmillisec: Time in milliseconds.
Associates a %TH task with an interrupt generated by timer A or B.
13 Timer Function
Operation
The call to thtimer() sets the timer whose number is given in timerno with the value specified in nbmillisec. When this
time has expired, the timer generates an IT used by the system to call the %TH task number thno.
The time nbmillisec is between 0 and 2,147,483,647 milliseconds.
Function thtimer() is modal, i.e. after the call to thtimer(), the %TH task is called cyclically every nbmillisec.
To cancel a thtimer() function, it is necessary to call thtimer() with parameter nbmillisec equal to ZERO.
The call to thtimer() while the timer is running causes a reset of the timer and a restart from nbmillisec.
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