9ć11, File instructions – Rockwell Automation 1785-LTx,D17856.2.1 Classic PLC-5 Programmable Controllers Users Manual User Manual
Page 128

Calculating Program Timing
Chapter 9
9-11
File Instructions
The instruction timing for file instructions depends on the data type,
number of files acted on per scan, number of elements acted on per scan,
and whether the instruction converts data between integer and floating
point formats.
Table 9.O shows PLC-5/10, -5/12, -5/15, and -5/25 processors. When you
use these tables, keep these guidelines in mind:
for integer to floating point conversion, add:
8
µ
s for each element address
10
µ
s for each file address (# prefix)
for floating point to integer conversion add:
33
µ
s for each element address
44
µ
s for each file address (# prefix)
Table 9.O
Timing and Memory Requirements for File Instructions
Category
Code Title
Time (
µ
s)
Integer
True
Time (
µ
s)
Floating point
True
Time (
µ
s)
Integer or
Floating Point
False
Words of
Memory
1
File Arithmetic and Logic
FAL
add
98 + W[36.7 + N] 98 + W[95.1 + N]
54
7Ć12
subtract
multiply
98 + W[42.5 + N] 98 + W[101.2 + N]
divide
98 + W[51.1 + N] 98 + W[180.3 + N]
square root
98 + W[84.7 + N] 98 + W[220.5 + N]
54
6Ć10
negate
98 + W[29.2 + N] 98 + W[37.2 + N]
clear
98 + W[18.4 + N] 98 + W[24.0 + N]
54
5Ć8
move
98 + W[27.3 + N] 98 + W[36.2 + N]
54
6Ć10
convert to BCD
98 + W[54.3 + N]
convert from BCD
98 + W[45.4 + N]
AND
98 + W[37.2 + N]
54
7Ć12
OR
98 + W[37.2 + N]
XOR
98 + W[37.2 + N]
NOT
98 + W[28.2 + N]
54
6Ć10
File Search and Compare FSC
all comparisons
93 + W[32.7 +N]
93 + W[43.3 +N]
W = number of elements acted on per scan
N = 2 x (number of integer file addresses) + 8 x (number of floatingĆpoint file addresses) + 6 x (number of timer, counter, or control
file addresses) + ( number of conversions between integer and floating point formats)
1
Use the smaller number if all addresses are below word 4096; use the larger number if all addresses are above 4096.