Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 232)

Preface MicroLogix 1000 Programmable Controllers User Manual
12–18
High-Speed Counter Load (HSL)
This instruction allows you to set the low and high presets, low and high output
source, and the output mask. When either a high or low preset is reached, you can
instantly update selected outputs.
If you are using the HSL instruction with the Up Counter, the high preset must be
≥
1 and
≤ +
32,767 or an error INVALID PRESETs LOADED TO HIGH SPEED
COUNTER (37H) occurs. For the bidirectional counters, the high preset must be
greater than the low preset or an error INVALID PRESETs LOADED TO HIGH
SPEED COUNTER (37H) occurs.
The Counter referenced by this instruction has the same address as the HSC
instruction counter and is fixed at C5:0.
Entering Parameters
Enter the following parameters when programming this instruction:
•
Source is an address that identifies the first of five data words used by the HSL.
The source can be either an integer or binary file element.
•
Length is the number of elements starting from the source. This number is
always 5.
Operation
The HSL instruction allows you to configure the high-speed counter to
instantaneously and automatically update external outputs whenever a high or low
preset is reached. The physical outputs are automatically updated in less than 30
µ
s.
(The physical turn-on time of the outputs is not included in this amount.) The
output image is then automatically updated at the next poll for user interrupts or
IOM instruction, whichever occurs first.
With this instruction, you can change the high preset for the up counters or both the
high and low presets for Bidirectional Counters during run. You can also modify
the output mask configuration during run.
The source address is either an integer or binary file element. For example, if N7:5
is selected as the source address, the additional parameters for the execution of this
instruction would appear as shown in the following table.
Execution Times
(µ
sec
)
when:
True False
66.00 7.00
HSL
HSC LOAD
Counter
C5:0
Source
Length
5
(DN)
(CU)