User`s manual

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MELSEC-Q
8 I/O CONTROL INSTRUCTIONS
Specified position
Symbo
l
Name Recommended range
*1
Unit Data format
Standard
value
Store
Loop tag
past value
memory
*2 *3
D2
+116
+117
Used by the system as a work area. S
*1: The data of the item(s) where the values within the recommended range are given in the parentheses are stored by the system.
Users cannot set the data.
*2: The loop tag memory and loop tag past value memory occupy a total of 128 words. (Refer to Section 3.3.1 for details.)
*3: The applications of the loop tag past value memory are indicated below.
Specified position Description
D2
+116
+117
E1
n-1
(Last input value)
When control is to be started from the initial status, the data must be cleared with the sequence program.
Processing contents
(1) Upper limit check processing
In the upper limit check processing, the following operation is performed and the result of the
operation is output to BB2 and PHA.
e1 e2 Input value increment (T1)
00
01
10 E1 E1
n-1
11
(2) Integrated value operation processing
In the integrated value operation processing, the following processing is performed for the
input value increment (T1).
e1 e2 Retentive value (Integer part) (T2), Retentive value (Fraction part) (T3)
00
T2
0
T3
0
01
T2
0
T3
0
*1
10
T4 quotient of {(T1 W) / U} <integer part>
T5
remainder of {(T1 W) / U} <fraction part>
T2
SUM1 T4 [quotient of {(SUM2 T5) / U}] <integer part>
T3
remainder of {(SUM2 T5) / U} <fraction part>
11
T2
SUM1
T3
SUM2
*1: At an integration stop/reset (e1 0), processing is performed on the assumption that integration hold
is canceled (e2
0).