Rockwell Automation 2080-LC50 Micro830 and Micro850 Programmable Controllers User Manual - Manual (Page 154)

138 Rockwell Automation Publication 2080-UM002F-EN-E - December 2013
Chapter 8 Use the High-Speed Counter and Programmable Limit Switch
PLS Data structure
The Programmable Limit Switch function is an additional set of operating modes
for the High Speed Counter. When operating in these modes, the preset and
output data values are updated using user supplied data each time one of the
presets is reached. These modes are programmed by providing a PLS data block
that contains the data sets to be used.
PLS data structure is a flexible array, with each element defined as follows,
The total number of elements for one PLS data cannot be larger than 255.
When PLS is not enabled, PLS data are still required to be defined, but can be
not initialized.
PLS Operation
When the PLS function is enabled, and the controller is in the run mode, the
HSC counts incoming pulses. When the count reaches the first preset (HSCHP
or HSCLP) defined in the PLS data, the output source data (HSCHPOutput or
HSCLPOutput) is written through the HSC mask (HSCAPP.OutputMask).
IMPORTANT The PLS Function only operates in tandem with the HSC of a Micro830
controller. To use the PLS function, an HSC must first be configured.
Element Order Data Type Element Description
Word 0…1 DINT High preset setting
Word 2…3 DINT Low preset setting
Word 4…5 UDINT High preset Output data
Word 6…7 UDINT Low preset Output data