Rockwell Automation 1761-HHP-B30 MicroLogix 1000 with Hand-Held Programmer (HHP) - Manual (Page 471)

Appendix E
Application Example Programs
E–28
Event Driven Sequencer Instruction List Program
File 2, Rung 0
Ensures that the SQO always resets to step (position) 1 each RRUN mode
entry. (This rung actually resets the control register’s position and EN
enable bit to 0. Due to this the following rung sees a false to true
transition and asserts step (position) 1 on the first scan.)
Eliminate this rung for retentive operation.
FUN GRAPHIC PARAMETER
CODE SYMBOL MNEMONIC NAME ADDRESS VALUE FORCES
–––– ––––––– –––––––– –––– ––––––– ––––– ––––––
20 |–] [– LD S1/15 0
7 RES R0
File 2, Rung 1
The SQC instruction and SQO instruction share the same Control Register.
This is acceptable due to the careful planning of the rung state
condition. You could cascade (branch) many more SQO instructions below the
SQO if you desired, all using the same Control Register (R6:0 in this
case). Notice that we are only comparing Inputs 0–3 and are only
asserting Outputs 0–3 (per our Mask value).
FUN GRAPHIC PARAMETER
CODE SYMBOL MNEMONIC NAME ADDRESS VALUE FORCES
–––– ––––––– –––––––– –––– ––––––– ––––– ––––––
20 |–]/[– LDI R0/FD 0
153 SQC FILE #N0
MASK 000FH
SRC I0
CTRL R0
LEN 9
POS 0000H
23 –]/[– ANI R0/FD 0
152 SQO FILE #N10
MASK 000FH
DEST O0
CTRL R0
LEN 9
POS 0000H