Yaskawa MP900 Series Ladder Programming Manual - Manual (Page 65)

4.7 Setting the High-speed/Low-speed Scan Times
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4.7 Setting the High-speed/Low-speed Scan Times
( 1 ) What Are the Scan Times?
With an MP2000-series Machine Controller, both the high-speed scan and low-speed scan can be set. The high-speed
scan time is the cycle at which high-speed drawings are executed. The low-speed scan time is the cycle at which low-
speed drawings are executed. The following table shows the possible set values and default values for each scan time.
Œ 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.
( 2 ) Scan Time Set Value Precautions
Observe the following precautions when setting the high-speed scan time and low-speed scan time.
• Set the scan set value so that it is 1.25 times greater than the maximum value.
ΠIf 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.
• 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.
• Do not change the scan set value while the Servo is ON. Never change the scan set values while an axis is in
motion (i.e., while the motor is rotating). Doing so may cause the motor to rotate out of control.
• After changing or setting the scan times, make sure to save the data to flash memory.
( 3 ) Checking and Setting the Scan Times
You can check the current and maximum values of the scan times and the set values of the scan times, and you can set
the scan times in the following dialog box of MPE720 Version 6.0.
Select File − Environment Setting − Setup − Scan Time Setting.
Item Possible Set Values Default
High-speed Scan Time 0.5 to 32 ms (in 0.5-ms increments) 10.0 ms
Low-speed Scan Time 2.0 to 300.0 ms (in 0.5-ms increments) 200.0 ms