Emerson PACSystems RSTi-EP User Manual page 188

User Manual
GFK-2958J
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For both counting modes 1-time counting and periodic counting you can parameterize the
counting range with load value and end value.
Via bit QX8.5 of the control word you can load a set value into the counting value. You can
define the set value in the second double word of the process data outputs.
Counting Direction
No primary direction
The entire counting range is available when using a counting mode without primary
direction.
Primary Direction Up
The counting range is limited at the top by a parameterized end value. Starting from 0, a set
value or a parameterized load value, the counter counts until the end value -1 and is reset
to the load value with the next encoder pulse.
Primary Direction Down
The counting range is limited at the bottom by a parameterized end value. Starting from 0,
a set value or a parameterized load value, the counter counts until the end value +1 and is
reset to the load value with the next encoder input.
Gate Function: Activate / Deactivate Counter
The counter is activated and deactivated using an internal gate. If the hardware gate (HW
gate) is deactivated in the parameters, the internal gate is identical to the software gate (SW
gate).
With activated hardware gate, there is a logic AND connection of SW gate and HW gate, so
that the gate functions operate exclusively on the HW gate. In this case, opening and closing
of the SW gate has an interrupting effect only.
The software gate is activated using a 0-1 edge at the bit Set SW gate in the control word
and deactivated with a 0-1 edge at the bit Reset SW gate in the control word (refer to the
table Process Data Outputs).
Counting Behavior: Cancel/Interrupt Counting
You can parameterize the counting behavior after a new gate start: Using Interrupt
counting, the counter continues from the last counting value. Using Cancel counting,
counting starts again from the load value.
Detailed Description of I/O Modules
Periodic counting with or without primary direction, for example, repeated identical
pick-and-place operations
Chapter 5
Oct 2019
173