Chapter 5 Detailed Descriptions of I/O Modules
GFK-2958E
RSTi-EP User Manual
194
Additional Counter Functions
Comparison Function
Via the parameter
Comparison function
you can deactivate the comparison function or define a
comparison condition:
–
–
Counter value higher or equal comparison value
–
–
Counter value lower or equal comparison value
–
–
Counter value equal comparison value
To use the comparison function, you have to preset the comparison values for both counting
channels in the respective first double word of the process data outputs and to set the bit QX8.1 and
QX10.1 respectively (
Comparison bit released
) in each control word.
As soon as the counting value meets the corresponding comparison condition, the bits
Comparison
bit active
and
Comparison condition met
are activated. The bit
Comparison bit active
remains set as
long as the comparison condition is being met (respectively the parameterised hysteresis). The bit
Comparison condition met
remains active until it will be reset with the bit
Reset of the status bits
in the
control word.
When using a counting mode with primary direction, the comparison bit will be set only upon
reaching the comparison value from the primary direction.
Hysteresis
It is possible to reduce frequent triggering of a process alarm and toggling of the comparison bit (e.g.
if the value of a sensor signal fluctuates around the comparison value), by setting the hysteresis. You
thereby define a range above and below a reference value (zero crossing, overflow/underflow and
comparison value), within which the status bit will not be reset.
A limit value between 0 and 255 can be parameterized for the hysteresis. With hysteresis = 3 for
example, all values differing less than 3 from the reference value are smoothed. Hysteresis is
deactivated with the values 0 and 1. The hysteresis is activated upon reaching the comparison
condition. The comparison result remains unchanged during active hysterersis until the counting
value reaches the predetermined hysteresis limit. After leaving the hysteresis range, hysteresis is
reactivated only upon reaching the comparison condition again.
Summary of Contents for RSTi-EP
Page 1: ...RSTi EP User Manual GFK 2958E November 2017...
Page 23: ...Chapter 1 Introduction GFK 2958E RSTi EP User Manual 19 Notes...
Page 56: ...Chapter 3 Configuration GFK 2958E RSTi EP User Manual 52 Notes...
Page 183: ...Chapter 5 Detailed Descriptions of I O Modules GFK 2958E RSTi EP User Manual 179 EP 5111...
Page 184: ...Chapter 5 Detailed Descriptions of I O Modules GFK 2958E RSTi EP User Manual 180 EP 5111...
Page 316: ...Chapter 5 Detailed Descriptions of I O Modules GFK 2958E RSTi EP User Manual 312 Notes...
Page 330: ...Chapter 6 Installation GFK 2958E RSTi EP User Manual 326 Notes...
Page 344: ...Chapter 7 Earthing and Shielding GFK 2958E RSTi EP User Manual 340...
Page 345: ...Chapter 7 Earthing and Shielding GFK 2958E RSTi EP User Manual 341 Notes...
Page 385: ...Chapter 8 Web Server GFK 2958E RSTi EP User Manual 381 Notes...
Page 401: ...Chapter 11 Disassembly and Disposal GFK 2958E RSTi EP User Manual 397 Notes...
Page 413: ...Chapter 12 LED Indicators and Troubleshooting GFK 2958E RSTi EP User Manual 409 Notes...
Page 416: ...Chapter 14Accessories and Replacement Parts GFK 2958E RSTi EP User Manual 412 Notes...