Finding limit switch without "fine tuning"

[jdb1986]

I am using NI motion assistant to first find forward limit, then perform a straight line move, then find reverse limit.  I need to do this without the "fine tuning" which is designed to slowly back away from limit switch then re-apporach slowly for a more accurate position.  For my application this is not needed and requires too much time.  How can I eliminate this "fine tuning".

Thanks,

Jacob

[Brian_Beal]

I was wondering why you need to use both limit switches for homing.  You should only need to use one or the other.

[Jochen]

Brian,

this type of homing routine is typically used if you don't know exactly the travel range of your stage and it is typically used if the same control software needs to run with various stages.

Jacob,

the Find Reference function is designed for accurate homing. If you don't need this accuracy, you shouldn't use Find Reference but start a move in velocity mode, wait until it hits the limit switch and start another move in velocity mode in the reverse direction. Then wait again until the second limit switch is hit. This means a bit more programming, but it eliminates the slow approaches towards the limit switches.

I hope this helps,

Jochen Klier

National Instruments

Message Edited by Jochen on 04-15-2010 09:18 AM