Tips on trolley project.

[GaryS]

Yes sometimes it does miss a flag or loose position. When this happens we take it back to station 1 and there is a reset button and goes back to last step completed.

That's a good reason to use a laser system they always read the correct position on power up
I have a system that has been doing exactly that for about 15 years we have never had to home it.
as for long distance cranes I have used laser system to read over 1,000 Ft with no problems and I know that there are system that will read in Miles if needed.

as for the prox reading tabs for position that is the way they did it in early
70's we can do better than that now
lest move systems forwards

 

[Jtec513]

Can you put the sensors on the trolley instead of at each station ? If they trolley were equipped with 5 sensors, you could have an array of trigger flags at each location to turn on sensors as a binary code.
00001 = Station 1
00010 = Station 2
00011 = Station 3
...
11111 = Station 31

I would not use prox switches for positioning way to much trouble
Use a laser measuring system, then write the code to have a teach mode

I have used both styles and they both work well with each their own drawback.

Limit switches/proxs tend to need a lot of maintenance since they break often or get dirty in the environment above the process tanks.

Lasers work really well as long as you keep the beam away from the steam generated from the hot tanks when the load is lifted out of them.