Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 271)

Chapter 14
Using High-Speed Counter Instructions
14–21
Operation
Execution of the RAC:
•
removes pending high-speed counter interrupts
•
resets the PE, LS, OV, UN, and DN status bits
•
loads a new accumulator value to the hardware and instruction image
•
loads the instruction high preset to the hardware high preset (if the
high-speed counter is configured as an Up Counter)
•
resets the IL, IH, IN, or IV status bits
The source can be a constant or any integer element in files 0–7. The
hardware and instruction accumulators are updated with the new accumulator
value immediately upon instruction execution.
You can have more than one RAC instruction per program referencing the
same source or different sources.
These instructions enable or disable a high-speed counter interrupt when a
high preset, low preset, overflow, or underflow is reached. Use the HSD and
HSE in pairs to provide accurate execution for your application.
The Counter referenced by these instructions has the same address as the
HSC instruction counter and is fixed at C0.
Using HSE
Entering the Instruction
You enter the instruction from within the program monitor functional area.
P 0 0 8 H S E C N T R
C 0 0
10.00
HSE
HSC INTERRUPT ENABLE
COUNTER
C5:0
Execution Times
(µ
sec
)
when:
True False
7.00
HSD
HSC INTERRUPT DISABLE
COUNTER
C5:0
8.00 7.00
HSE
HSD
Ladder representation:
High-Speed Counter Interrupt
Enable (HSE) and Disable (HSD)
3
U
7
ENT
1
FUN
To enter the function code, press: