Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 251)

14 Chapter
14–1
Using High-Speed Counter Instructions
This chapter contains general information about the high-speed counter
instructions and explains how they function in your application program.
Each of the instructions includes information on:
•
what the instruction symbol looks like
•
typical execution time for the instruction
•
how to use the instruction
•
how to enter the instruction
•
what happens to the HSC when going to the RRUN mode
In addition, the last section contains an application example for a paper
drilling machine that shows the high-speed counter instructions in use.
High-Speed Counter Instructions
Mnemonic
Function
Code
Name Purpose Page
HSC 170 High-Speed Counter
Applies configuration to the high-speed counter hardware, updates the
image accumulator, enables counting when the HSC rung is true, and
disables counting when the HSC rung is false.
14–4
HSL 171 High-Speed Counter Load
Configures the low and high presets, the output patterns, and mask bit
patterns.
14–15
RES 7 High-Speed Counter Reset Writes a zero to the hardware accumulator and image accumulator. 14–19
RAC 172
High-Speed Counter Reset
Accumulator Writes the value specified to the hardware accumulator and image
accumulator.
14–20
HSE
HSD
173
174
High-Speed Counter
Interrupt Enable
High-Speed Counter
Interrupt Disable
Enables or disables execution of the high-speed counter interrupt
subroutine when a high preset, low preset, overflow, or underflow is
reached.
14–21
OUT 40
Update High-Speed
Counter Image Accumulator Provides you with real-time access to the hardware accumulator value by
updating the image accumulator.
14–23
The high-speed counter instructions used in your program configure, control,
and monitor the controllers’ hardware counter. The hardware counter’s
accumulator increments or decrements in response to external input signals.
When the high-speed counter is enabled, data table counter C0 is used by the
program for monitoring the high-speed counter accumulator and status. The
high-speed counter operates independent to the controller scan.
Since these are output instructions, they do not have LD, AND, and OR
equivalents.
When using the high-speed counter, make sure you adjust your input filters
accordingly. See page 18–12 for more information on input filters.
Before you learn about these instructions, read the overview that follows on
the next page. Refer to page 2–23 for information on wiring your controller
for high-speed counter applications.
About the High-Speed
Counter Instructions