Allen-Bradley ClutchBrake PLC-5 Series - Page 161

Programming Considerations for PLC-5 Processors F–3
Publication 65566.5.1 - October 1996
Table F.A
Typical
Execution T imes for Selected Instructions for PLC5/1 1, 20, 30 Processors
Type of Instruction
If False (approx ms) If True (approx ms)
relay, such as examine, energize, latch, and unlatch 0.2 0.4
timer and counter 3 4
arithmetic, such as add, subtract, multiply, divide 1.5 4 - 12
trig functions, such as sin, cos, tan, 1.5 375 - 500
move and compare 1 4
shift register, such as shift left/right, load, and unload
bit dependent, where n = number of bits operated on
4 10 + n(0.025)
immediate I/O: time to queue up for processing 1 300 - 360
process control, such as PID gain computation 3 500 - 900
block transfer: (transfer time for 10word transfer ,
first in queue, 1 full remote logical rack, 57.6K baud)
3 500 - 1000
Processor Family
Some processor families are faster at executing selected groups of
instructions than other processor families (Table F.B).
Table F.B
Comparing
Processors for T ypical If T rue" Execution T imes
Type of Instruction PLC5/11, 20, 30, 40, 80 PLC5/10, 12, 15, 25
relay, such as examine, energize, latch, and unlatch 0.4 1.5
timer and counter 4 30 - 44
arithmetic, such as add, subtract, multiply, divide 4 - 12 18 - 82
trig functions, such as sin, cos, tan, 375 - 500 cannot do it
move and compare 4 26 - 63
shift register, such as shift left/right, load, and unload
depends on number of bits or words operated on
10 + n(0.025)
n = number of bits
90 +4w
w = # of words
subroutine jump/return instructions (p = # of parameters) 12 + 4p 56 + 21p
immediate I/O: time to queue up for processing 300 - 360 160 - 200
process control, such as PID gain computation 500 - 900 600
block transfer: (transfer time for 10word transfer ,
first in queue, 1 full remote logical rack, 57.6K baud)
500 - 1,000 600