Wednesday, July 24, 2013

Vision systems need utility tools

Are you the only person who can make changes to your inspection system? If so, either you like those 3 a.m. phone calls when it starts rejecting everything, or you’ve implemented the world’s most robust machine vision system. Congratulations.

Most of us want to let other people log on and make changes. Trouble is, when you arrive on site and want to diagnose a vision system problem there’s often no way of knowing who did what and when.

That’s why a simple set of utility tools should always be part of every system. I suggest they do the following:

  • Require a sign-in to access the vision software. Consider multiple levels of access, so an operator can load a new part file but only an engineer can alter exposure time.
  • Write that sign-in data to a .txt file, along with the date and time.
  • Log every time a change to the part file is saved, and ideally, log that change. So if a size limit is moved from 25 to 26mm you’ll know.
  • Do the same with camera and I/O parameters. Write down every change to the log.

You might like to go further and gather stats on system availability and run time. This would let you know if the system was being starved of parts as well as helping judge when maintenance might be needed. For example, you might log how many hours the lights have been on.

Yes this is all extra coding, and your ability to do it will be related to the platform you’re using: a vision sensor will not have the programming flexibility of a PC-based system. But down the road, it’s going to save you time. In fact your biggest challenge will be finding Jane Doe to ask why she bumped a threshold up by two points.

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