West Control Solutions CALogix - Manual (Page 34)

II. Timers
A number of timer functions are available with CALogix, these are: on-delay, off-delay, on-off delay, on-pulse,
off-pulse, on-off pulse, delayed-pulse, symmetrical recycler pause, symmetrical recycler pulse, asymmetrical
recycler pause and asymmetrical recycler-pulse. Timer charts showing the operation of these are shown in
appendix
The time settings are entered by clicking on the time required and entering the data in HHH.MM.SS.S format.
Once entered click on OK to accept the settings change.
All timers require a single input from either an input block or another function block. The block output must be
connected to another function block or an output block.
Time settings for standard timer types are set via CALogix software. To adjust timer settings remotely via an
operator panel, SCADA or field device ensure that the ‘remote’ box is ticked in the function block ‘properties’.
This feature is only available for ‘on’ and ‘off’ delay timers, other timer types can be created from these basic
timer blocks, contact CAL for more information. The data register in which the timer can be accessed remotely
is shown outlined in the function block when the logic program has been downloaded to CALogix, see below.
Timer value is stored in register, 2824 (dec)
III. Counters (select timer block)
Counters blocks will give an output after the input has received a user specified number of input pulses. Two
types of counter blocks can be selected counter reset and high speed counter. The high speed counter can
count pulses up to 1kHz and counter reset to a frequency of 10Hz. Otherwise both counters function in a similar
way.
If using a high speed counter, the physical input for the counter must be from input 1 on the logic I/O module.
To set a count value, enter the required number in counts.
A counter requires two inputs to operate, a count input and a control input. As pulses are received at the count
input the counter will increment, an output is given when the set number of counts is received. The counts
received will reset to 0 when the control input goes to a high-state (1), the block output is also reset to a low-
state (0) if the count value had been previously reached.
The operation of each of the input 1 and 2 can be selected in the properties window shown above.
It is also possible to select whether the counter will increment on a rising edge (low to high state) or level
triggered (i.e. when input reaches and is stable at a high state). This is set within the trigger parameter within
the properties window.
IV. Comparator
Comparator blocks take a voltage level from a logic I/O module and compare the value with either a constant or
the value of another logic I/O module input.
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