Rockwell Automation 1761 MicroLogix 1000 Programmable Controllers - Manual (Page 309)

Reference
Programming Reference
B–21
Instruction Execution Times and Memory Usage
The table below lists the execution times and memory usage for the controller
instructions. Any instruction that takes longer than 15
µ
s (true or false execution
time) to execute performs a poll for user interrupts.
Mnemonic
False Execution
Time (approx.
µ
seconds)
True Execution
Time (approx.
µ
seconds)
Memory Usage
(user words)
Name Instruction Type
ADD 6.78 33.09 1.50 Add Math
AND 6.78 34.00 1.50 And Data Handling
BSL 19.80
53.71 + 5.24 x
position value
2.00 Bit Shift Left
Application
Specific
BSR 19.80
53.34 + 3.98 x
position value
2.00 Bit Shift Right
Application
Specific
CLR 4.25 20.80 1.00 Clear Math
COP 6.60 27.31 + 5.06/word 1.50 File Copy Data Handling
CTD 27.22 32.19 1.00 Count Down Basic
CTU 26.67 29.84 1.00 Count Up Basic
DCD 6.78 27.67 1.50
Decode 4 to 1 of
16
Data Handling
DDV 6.78 157.06 1.00 Double Divide Math
DIV 6.78 147.87 1.50 Divide Math
ENC 6.78 54.80 1.50
Encode 1 of 16 to
4
Data Handling
EQU 6.60 21.52 1.50 Equal Comparison
FFL 33.67 61.13 1.50 FIFO Load Data Handling
FFU 34.90
73.78 + 4.34 x
position value
1.50 FIFO Unload Data Handling
FLL 6.60 26.86 + 3.62/word 1.50 Fill File Data Handling
FRD 5.52 56.88 1.00 Convert from BCD Data Handling
GEQ 6.60 23.60 1.50
Greater Than or
Equal
Comparison
GRT 6.60 23.60 1.50 Greater Than Comparison
HSC 21.00 21.00 1.00
High-Speed
Counter High-Speed
Counter