Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 238)

Chapter 13
Using Application Specific Instructions
13–12
The SQL instruction stores 16-bit data into a sequencer load file at each step
of sequencer operation. The source of this data can be an I/O or internal
word address, a file address, or a constant.
Entering Parameters
Enter the following parameters when programming this instruction:
•
File is the address of the sequencer file. You must use the file indicator
(#) for this address. (The HHP inserts the # character automatically.)
•
Source can be a word address, file address, or a constant (–32,768 to
32,767).
If the source is a file address, the file length equals the length of the
sequencer load file. The two files step automatically, according to the
position value.
•
Length is the number of steps of the sequencer load file (and also of the
source if the source is a file address), starting at position 1. The
maximum number you can enter is 104 words. Position 0 is the startup
position. The instruction resets (wraps) to position 1 at each cycle
completion.
•
Position is the word location or step in the sequencer file to which data is
moved.
•
Control is a control file address. The status bits, length value, and
position value are stored in this element. Do not use the control file
address for any other instruction.
The control element is shown below:
EN DN ER
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00
Length
Position
Word 0
Word 1
Word 2
Status bits of the control structure include:
– Error Bit ER (bit 11) is set when the controller detects a negative
position value or a negative or zero length value. When the ER bit is
set, the minor error bit (S2) is also set. Both bits must be cleared.
– Done Bit DN (bit 13) is set after the instruction has operated on the
last word in the sequencer load file. It is reset on the next false-to-true
rung transition after the rung goes false.
– Enable Bit EN (bit 15) is set on a false-to-true transition of the SQL
rung and reset on a true-to-false transition.
(EN)
(DN)
SQL
SEQUENCER LOAD
File
#B3:8
Source I:0.0
Control R6:3
Length 4
Position 2
Execution Times (
µ
sec) when:
True False
53.41 28.12
Ladder representation:
Sequencer Load (SQL)