Yaskawa MotionWorks IEC - Manual (Page 378)

PLCopenPlus Function Blocks for Motion Control 2013-04-13 370
Engage / Disengage Window
The optimal Engage or Disengage Window requires knowing the fastest
master speed at which the machine is expected to operate. The window
must be large enough to ensure that the motion engine, executing at the
MECHATROLINK update rate can see the master position within the
window during one scan. Yaskawa recommends setting the window to the
distance the master can travel in two scans.
1. Convert maximum expected master speed into the same units as
configured for the master axis.
2. Determine the MECHATROLINK update rate or Dual Port RAM update
interval (MP2600iec.) by looking in the Hardware Configuration.
3. Convert to find the distance the master can travel in one
MECHATROLINK update interval.
4. Double the scan rate for safety margin.
Maximum expected speed: 500 ft/min.
Convert to configured user units of ft/sec: 500 / 60 = 8.333 ft/sec.
MECHATROLINK update rate = 2 mSec.
Invert update rate to find number of scans per second: 1000 / 2 = 500.
Maximum distance travelled per scan: 8.333 / 500 = 0.016666 feet.
Double for safety margin: 0.03333.