• Skip to primary navigation
  • Skip to main content
  • Skip to primary sidebar
  • Skip to footer

Motion Control Tips

Automation • Motion Control • Power Transmission

  • News
    • Industry News
    • Editor Blogs
    • Video
  • Controls
    • HMIs
    • PC-Based Controllers
    • PLCs + PACs
    • Stand-Alone Controllers
    • Software
  • Drives
    • Servo Drives
    • Stepper Drives
  • Encoders
    • Absolute Encoders
    • Incremental Encoders
    • Rotary Encoders
  • Mechanical
    • Bearings
    • Brakes + Clutches
    • Belt + chain
    • Couplings
    • Gears + Gearing
    • Lubrication
    • Shock + Vibration Mitigation
    • Springs + Rings + Seals
  • Linear
    • Actuators
    • Linear Motors
    • Linear Encoders
  • Motors
    • AC Motors
    • DC Motors
    • Brushless Motors
    • Gearmotors
    • Piezo Motors
    • Servo Motors
    • Stepper Motors
  • Systems
    • Conveyors + linear transport systems
    • Gantries + Stages
    • Rotary Tables
    • Grippers + End Effectors
    • Robotics
  • Networks
    • Connections + Sliprings
    • Fieldbuses
    • I/O
    • Sensors + Vision
  • FAQs
    • Motion Casebook
    • Motion Selection Guides
  • Suppliers
You are here: Home / Controls / What are breakpoints and how are they used in motion control?

What are breakpoints and how are they used in motion control?

May 12, 2021 By Danielle Collins Leave a Comment

In computer programs, breakpoints are functions within the code that help with monitoring and debugging the program. The programmer can mark, or flag, a line of code as a breakpoint, and when the program encounters the breakpoint marker, it pauses before executing that line of code. This allows the programmer to inspect variables, I/O status, registers, and other parts of the program to troubleshoot problems, make edits, and ensure the program is performing correctly.

In some cases, once a breakpoint is reached, the programmer will run the program in “step mode,” where the program stops after each line or executable statement, so the developer can analyze the program’s performance and find errors. Breakpoints can be assigned (or removed) before a program is started or, in many cases, during the program execution.

Breakpoints are useful debugging tools when programming motion controllers, since motion applications often involve complex programs with many variables, I/O devices, and conditional statements.

breakpoints
In this robot control program, a breakpoint is indicated by the red line after the “Move-Wayport_3” command.
Image credit: Universal Robots

In motion control, breakpoints can also be used in the actual execution of the motion program, as a means for initiating an action based on a specified condition. The action, or event, caused by the breakpoint can be a controlled or abrupt stop, and update to a register, or even a change in motion parameters.

The condition that causes the breakpoint to activate is often referred to as the trigger. This trigger can be a threshold, where a parameter reaches or crosses a specified value (typically defined as “equal to or greater than” or “equal to or less than”) or it can be a level, when a parameter changes state.

For example, two common breakpoint triggers are position and velocity, both of which are typically defined as thresholds (i.e., position equal to or less than 3000; velocity equal to or greater than 1.5). Position-based breakpoints can be defined as absolute or relative position values and are often used for triggering external events. Breakpoints can also be based on external triggers, such as the status of or a signal from an external device.

Some controllers also offer advanced breakpoint functions, such as buffered breakpoints and periodic breakpoints. A buffered breakpoint is simply an array of breakpoints that is pre-loaded into the motion controller, so that the next breakpoint is automatically set up once the preceding breakpoint is triggered. Periodic breakpoints are triggers that occur at exact, fixed intervals.

breakpoint
Periodic breakpoints require an initial breakpoint and a breakpoint period. Here, the initial breakpoint is at 100 counts, and the period is 1000.
Image credit: National Instruments

One common use of breakpoints is to synchronize the motion of an axis with an external image or data acquisition device. Here, the trigger is typically the absolute or relative position of the axis, and the event is the activation of the device to capture an image or data at that precise position.

In a multi-axis system, a breakpoint can be triggered by one axis, while the event is an action on a different axis. For example, the trigger could be the status change of a limit switch on “axis 1,” and the resulting event could be a change to the motion profile of “axis 2.”

breakpoint
An external trigger can be used with a multi-axis system to create a synchronized event, such as a change in velocity, on all the axes.
Image credit: Performance Motion Devices

You may also like:

  • encoder
    Programmability is a key encoder design trend

  • What does software for motion controllers look like?

  • Programmable automation controllers (PACs) work as an alternative to what…

  • How to program a motion controller?

  • 3 Omron engineers answer 7 FAQs on controllers and PC-based…

Filed Under: Controls, FAQs + basics, Featured

Reader Interactions

Leave a Reply

You must be logged in to post a comment.

Primary Sidebar

POWER TRANSMISSION REFERENCE GUIDE

DESIGN GUIDE LIBRARY

“motion
Subscribe Today

RSS Featured White Papers

  • Specifying electric rodless actuators: Ten tips for maximizing actuator life and system performance
  • The truth about actuator life: Screw drive survival
  • Top Ten Tips: How to specify electric rod-style actuators for optimal performance, reliability and efficiency

Footer

Motion Control Tips

DESIGN WORLD NETWORK

Design World Online
The Robot Report
Coupling Tips
Linear Motion Tips
Bearing Tips
Fastener Engineering.

MOTION CONTROL TIPS

Subscribe to our newsletter
Advertise with us
Contact us
About us
Follow us on TwitterAdd us on FacebookAdd us on LinkedInAdd us on YouTubeAdd us on Instagram

Copyright © 2022 · WTWH Media LLC and its licensors. All rights reserved.
The material on this site may not be reproduced, distributed, transmitted, cached or otherwise used, except with the prior written permission of WTWH Media.

Privacy Policy | RSS