Allen
Jun 22 2004, 08:43 PM
I WOULD LIKE TO SEE IF ANYBODY HAS ANY CODE OR SAMPLE PROGRAM UTILIZING A PROX AND A SPROCKET TO DETERMINE HOW FAR A CONVEYOR HAS MOVED FPM.
Skidog
Jun 23 2004, 01:33 AM
Easy enough to do. You'll need to 'beef up' one area of the sprocket with piece of plate steel twice the diameter in length as your prox head. Mount the prox close enough to the sprocket to cause the metal you added to trip the prox with each pass.
Now figure out how far the conveyor travels for every one revolution of the sprocket. Write this down, you'll need this later.
There a several ways to do this now. First you'll need to determine what standard of measurement your going to use, english or metric.
Next, you'll have to decide how accurate you want this device to be, that will determine the measurement units, i.e inches-feet-yards or mm-cm etc. Your accuracy will increase with each sensor plate you add to the sprocket.
Will you need to 'calibrate' the conveyor belt to control the point at which it stops? I would suggest another prox and trip bar, only this time, mount the trip bar on the conveyor itself. When this bar is sensed, you'll zero the count.
Now for some ladder logic.
Try a box instruction or two, they're always fun. Remember to include direction information in your program. If the conveyor moves forward, increment the count. If the conveyor moves backwards, decrement the count.
If I have time tomorrow I'll bang out a sample ladder and post it.
Have fun!
Skidog
Jun 23 2004, 11:32 AM
I don't think I made something clear with regards to the accuracy of this device.
If you use a narrow plate to trip the prox as opposed to a wide one, the accuracy will increase. If you use several narrow plates, the accuracy improves that much more.
More later..busy.
Allen
Jun 24 2004, 11:25 AM
Thanks Skidog
We put together some code, and we read all teeth on sprocket.
I will post code after finalized.
Thanks again for input.