Rules of use for "Move Absolute (20)"

Discuss and troubleshoot RMCTools along with RMC70, RMC150, and RMC200 motion controllers.

Rules of use for "Move Absolute (20)"

Postby lamboom » Mon Jan 01, 2018 8:33 am

I've got about 25 user programs in a RMC75E-QA2 .. all happily making two LinMot linear actuators generate waves in a small model ocean. The actuators start and finish at an "initial" position (0.0), and some programs use offsets, and often shift the wave making "sequence start" position. If a sequence is stopped, the stop program also returns the actuator to it's initial position. So... most of the programs were written assuming the actuator would be at 0.0 when the program is initiated.

Turns out, sometimes it isin't. Methinks a good programmer would make sure the actuator is "in position" before starting... and if not in position, send it there.. :D

I've always thought Move Absolute (20) was the solution to such potential problems.. but, sniff, i can't make it work. Here's an example of a simple program that creates a fault if the actuator isn't at zero, when started:
Regular Wave starting at zero.jpg
Regular Wave starting at zero.jpg (43.52 KiB) Viewed 48 times


Below, I thought would be the solution:
Regular Wave move to zero then start.jpg
Regular Wave move to zero then start.jpg (59.27 KiB) Viewed 48 times


worked fine if the actuator was already at zero.. but jog it a little away from zero.. and the Move Absolute (20) .. doesn't bring it back to zero when the program is started. same fault with too high a position discontinuity.

been reading RMC TOOLS .. don't see any clues to a solution yet...
lamboom
 
Posts: 35
Joined: Sun Mar 23, 2014 12:01 pm

Re: Rules of use for "Move Absolute (20)"

Postby Peter Nachtwey » Mon Jan 01, 2018 8:52 pm

Something is keeping the actuator from moving to 0.0. Show a plot. Are there any errors?
Peter Nachtwey
 
Posts: 154
Joined: Wed Jan 02, 2008 5:58 pm

Re: Rules of use for "Move Absolute (20)"

Postby lamboom » Tue Jan 02, 2018 7:52 am

Happy New Year Peter... Thanks for the fast reply, and YES there is an error or fault. I will plot curves, and present all into on the fault that I can find.
You didn't mention my "Fix" to the program as a solution that ought to work ... :-)

Was I correct in assuming Move Absolute (20) could start any positioning program, regardless of where the actuator was last stopped?
lamboom
 
Posts: 35
Joined: Sun Mar 23, 2014 12:01 pm

Re: Rules of use for "Move Absolute (20)"

Postby Jacob Paso » Tue Jan 02, 2018 2:36 pm

Yes, I think your fix should work.
Jacob Paso
 
Posts: 500
Joined: Thu Jan 03, 2008 3:18 pm

Re: Rules of use for "Move Absolute (20)"

Postby lamboom » Tue Jan 02, 2018 4:02 pm

..then this is indeed, a worthy challenge to resolve. I'm on it!
lamboom
 
Posts: 35
Joined: Sun Mar 23, 2014 12:01 pm

Re: Rules of use for "Move Absolute (20)"

Postby lamboom » Wed Jan 03, 2018 7:27 am

Aaaaaagh... GADZOOKS! .. I've made a horrible mistake .. I have so many programs in the "program" I didn't realize my example program works fine... some of the commands from the HMI just call a Sine Start (72) .. an' that's not a user program .. it's a nice feature of the RMCs' DUH! .. My program names were too similar .. There's nothing wrong.. nothing to see here.. these are not the droids you're looking for. :oops:
lamboom
 
Posts: 35
Joined: Sun Mar 23, 2014 12:01 pm

Re: Rules of use for "Move Absolute (20)"

Postby Jacob Paso » Wed Jan 03, 2018 9:13 am

A nice feature of the RMC is that multiple sources can send commands to it. This helps create the confusion and bewilderment necessary for providing enough stress in life. A life with no stress is not healthy. Of course, that may not be a serious problem in this specific situation.
Jacob Paso
 
Posts: 500
Joined: Thu Jan 03, 2008 3:18 pm


Return to RMCTools

Who is online

Users browsing this forum: No registered users and 2 guests