3.1 Basic Functionality
Scans
3-35
3
CPU Unit Functionality
2.
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.
3.
Select
Setup
−
Scan Time Setting
.
The following dialog box will be displayed.
Setting Value:
Enter the scan time settings.
Current Value:
A value of 0.0 ms is displayed when the MPE720 is offline. Otherwise, the actual pro-
cessing times for the scans are displayed.
Maximum Value: The maximum processing time for the scan is displayed. You can set the maximum
value. The setting is retained until it is exceeded.
4.
Enter the high-speed scan time in the
Setting Value
Box under
High-speed Scan
. Enter the low-
speed scan time in the
Setting Value
Box under
Low-speed Scan
.
The following table shows the possible set values and default values for each scan time.
Note: The possible set values and default values depend on the model. Refer to the user’s manual for the Module
you are using for details.
5.
Click the
OK
Button.
The settings will be saved and the Environment Setting Dialog Box will close.
Item
Possible Set Values
Default
High-speed Scan Time
0.125 to 32 ms (in 0.125-ms increments)
4.0 ms
Low-speed Scan Time
2.0 to 300.0 ms (in 0.5-ms increments)
200.0 ms
Observe the following precautions when setting the high-speed scan time and low-speed
scan time.
1. Set the scan set value so that it is 1.25 times greater than the maximum value.
If the scan set value is too close to the maximum value, the refresh rate of the MPE720 window will
noticeably drop and can cause communications timeout errors to occur. If the maximum value
exceeds the scan set value, a watchdog error may occur and cause the Machine Controller system to
shut down.
2. If you are using MECHATROLINK-II or MECHATROLINK-III, set values that are an integral
multiple of the communications cycle. If you change the communications cycle, check the scan time
set values.
3. Do not change the scan set value while the Servo is ON. Never change the scan set value while an
axis is in motion (i.e., while the motor is rotating). Doing so may cause the motor to rotate out of
control.
4. After changing or setting a scan time, always save the data to flash memory.
Important
