Position-Based Limit Switch Operation 1756-PLS

Configure a single limit switch with Setpoints to turn ON and OFF once, multiple times, or cyclically during a single resolver rotation.
set point (SP)
The variable representing the commanded state or value of the process being controlled in a feedback control loop.
Low and High Limit Setpoints
Configure low limit and high limit Setpoints to determine when an output is energized. This feature allows you to set particular points in the resolver’s rotation where, when reached, the output specified by the Output ID turns ON and OFF, as shown in the image.
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Configure multiple pairs of Setpoints in a single resolver rotation for a single output. For example, you can configure an output to turn ON at 15 degrees, OFF at 45 degrees, ON at 60 degrees, OFF at 100 degrees, and so forth, with each low limit and high limit pair representing a single setpoint.
Stitching Setpoints
Stitch Setpoints allow you to cycle outputs ON and OFF for a series of specific distance intervals without configuring separate ON-OFF Setpoints for each interval. When using this feature, the series of OFF to ON to OFF transitions occur within the configured low limit-high limit setpoint region.
For example, starting at 45 degrees, you may want to turn an output ON for 15 degrees, then turn it OFF for 15 degrees and repeat this sequence until 180 degrees, as shown in the image. Configure ON-OFF Setpoints for each transition or use stitching Setpoints.
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When using Stitching Setpoints, you configure these fields:
  • Enable the Enable Stitching Setpoints - enables the feature
  • Setpoints Low Limit Position - the beginning of the cycle window
  • Setpoints High Limit Position - the ending of the cycle window
  • Setpoints ON Stitch Distance - the distance that the output remains ON
  • Setpoints OFF Stitch Distance - the distance that the output remains OFF before turning ON again
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