3.1 Basic Functionality
Scans
3-36
Keep Latest Value Setting in High-speed/Low-speed Scans
You can use the Keep Latest Value setting to specify the number of scans to hold previous data when an
input error occurs. If the input error still exists after the number of scans specified for the Keep Latest
Value setting, the input values will be treated as 0. When the input error is removed, reading the input val-
ues is resumed automatically. There are separate Keep Latest Value settings for the high-speed scan and
the low-speed scan.
Operation
The following figure illustrates the operation for the Keep Latest Value setting.
Keep Latest Value setting: 3 scans for high-speed scan
Setting Procedure
Perform the following procedure with MPE720 version 7 to set the Keep Latest Value setting.
1.
Select
File
−
Environment Setting
from the menu bar. Alternatively, click the
System Setting
Icon on the Start Tab Page.
The Environment Setting Dialog Box will be displayed.
2.
Select
Setup
−
System Setting
.
The following dialog box will be displayed.
3.
Set values in the
High-speed Input
and
Low-speed Input
Boxes in the
Keep Latest Value
Group.
High-speed scan
Keep Latest Value region:
The value from before
the input error (201) is held for 3 scans.
100
101
102
103
104
105
200
201
201
0
106
107
207
Input value
to I/O
Module 1
Input value
to I/O
Module 2
The number of scans
set for the Keep Latest
Value setting was
exceeded, so the input
value is treated as 0.
Reading the input
value is automati-
cally started again.
Input error occurred in
I/O Module 2.
Input error removed
from I/O Module 2.
