Electronic gearing rollover problem

[jag]

I'm using a PCI-7344 in open loop stepper mode, axis 1 is the master and axis 2 is electronicly geared to axis 1 with a ratio less than one. The problem is when the master axis position rolls-over from positive 2,147,483,647 to negative 2,147,483,648 and then the gearing ratio is changed, the following axis (axis 2) stops for a period of time. I'm using NI-Motion 6.15.

[RManion]

Hi jag,

Thanks for using the NI Discussion Forums. Hopefully we can get everything worked out quickly!

This is an interesting problem, and due to the large number of steps needed to resproduce the issue, it is a problem I have not encountered before. That said, I will be doing some testing over the next couple of days to see if we can find a fix or work around for this issue. Hopefully, the 7344 does not always behave this way.

To help resolve this issue, I have a couple of questions regarding the 7344's behavior.

When you say that the motion pauses for a period of time, how long do you mean?
Does the pause occur at the rollover position, or when you change the gearing ratio?
Doe the pause only occur if you change the gearing ratio?

Thanks,

Robert

[jag]

It appears that the amount of time that it pauses varys. The pause occurs when the gear ratio is changed, but only when the master axis counter has previously rolled-over.

[RManion]

Hello again jag,

I forgot yesterday to ask you a very important question: Is your electronic gearing setup to be absolute or relative?

Thanks,

Robert

[ChadE]

R&D has reproduced this gearing issue and I will post a reply to this thread when we have a fix.

Regards,

[ChadE]

Hello jag,

We will have the fix to this in our next version of NI-Motion (i.e. later than 6.1.5). I will contact you directly to talk about your time frame.

Regards,