Rockwell Automation 1772-L8_LW_LWP_LX_LXP,D17726.5.8 User Manual User Manual
Page 122
Scan Theory
Chapter 8
8-4
Add the execution values for each instruction by using Table 8.A. The
sum of these values added to the I/O scan time is the average scan time.
Table 8.A
These Are the Approximate Execution Time Per Scan (in average
microseconds) and Words Per Scan for Each Instruction
Instruction
Instruction Name
Symbol
True
average
µ
sec.
False average
µ
sec.
Words Per
Instruction
These instructions are features of the MiniĆPLCĆ2/02, MiniĆPLCĆ2/16, and MiniĆPLCĆ2/17
Examine On
Examine Off
Output Energize
Output Latch
Output Unlatch
-[ ]-
-[ / ]-
-( )-
-(L)-
-(U)-
7
5
8
7
7
10
10
10
10
10
6
5
8
6
6
10
10
10
10
10
1
1
1
1
1
1
1
1
1
1
Get
Put
Equal
Less Than
Get Byte
Limit Test
-[G]-
-(PUT)-
-(=)-
-(<)-
-]B[-
-]L[-
15
12
12
14
11
13
10
10
10
10
10
10
-
7
13
13
-
14
10
10
10
1
1
1
1
1
1
1
1
1
1
1
1
Counter Reset
Retentive Timer Reset
Timer OnĆDelay
Retentive Timer OnĆDelay
Timer OffĆDelay
Up Counter
Down Counter
-(CTR)-
-(RTR)-
-(TON)-
-(RTO)-
-(CTD)-
-(CTU)-
-(CTD)-
19
19
51
52
55
38
36
6
6
36
33
39
30
31
1
1
1
1
1
1
1
add 1 word per instruction when its address is 400
8
or greater
add 2 words per instruction when its address is 400
8
or greater
1 word
999 words
1 bit
999 bits
with 2 data values
with 10 data values
with 50 data values
add 8
µ
s per instruction when its address is 400
8
or greater
add 16
µ
s per instruction when its address is 400
8
or greater
1
2
3
4
5
6
7
8
9
10
11