Jump to content

Logic question - M91

Recommended Posts

OK, new problem to solve... I am really stumped trying to solve a logic issue with my M91 project. Here's the scenario:

I have an analog transducer that is mechanically tied to a piece of machinery that moves in a linear motion. (Up and down)

The M91 shows the relative distance from the floor, in inches... and I can set a 'new' height value which causes an output to energize that closes a motor contactor to run a motor to move the machine up or down.

That part all works great. :rolleyes:

What I am struggling with is the logic to display a message in the event of a failure to actually move the machine, for a variety of reasons. The hard part is that the machine moves *very* slowly, and can take as much as 10 minutes to move from the lowest point to the highest point.... but, I want the 'failure' message (display) to occur if there is no actual movement within 5-10 seconds.

With the 'math' and 'compare' functions that I have available to me in the M91 ladder, I can't seem to find the "right" methodolgy to make this work! :wacko:

Any ideas would be greatly appreciated!


Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...