GE GFK-2958E, User Manual

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Chapter 5 Detailed Descriptions of I/O Modules
GFK-2958E RSTi-EP User Manual 188
5.15.1 Setting Up the Counter
To start a counting process at least the signal mode needs to be parameterized and a rising flank at
the bit QX8.2 or QX10.2 respectively (
Set SW gate ) of the control word is required.
You can define the counter functions by parameterizing: the counting mode, a primary direction
(counting up or down), and the counting behaviour. In addition you can parameterize options for
setting a comparison bit (conditions, hysteresis) as well as producing a process alarm (refer to the
section section,
Additional Counter Features ).
Counting Range, count Limits
The maximum count limits are predetermined by the register size and cannot be changed.
Counting Range
Limits Valid range of values
Lower count limit – 2 147 483 648 ( – 2 31 )
Upper count limit +2 147 483 647 (2 31 – 1)
5.15.2 Counter Functions
Counting Mode
Depending on the application you can chose the counting mode:
•
Endless counting, e.g. for detecting the position with a rotary encoder
•
1-time counting with or without primary direction, e.g. for counting products up to a
maximum limit
•
Periodic counting with or without primary direction, e.g. repeated identical pick-and-place
operations
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 or QX10.5 respectively of the control word you can load a set value into the counting
value. You can define the set value in the module parameters.
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 pulse.
Gate Function Activate / deactivate Counter
The counter is activated and deactivated using an internal gate. The internal gate is identical to the
software gate (SW gate), it 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 (see table Process data
outputs ).