Query stepper-motor indexer

[Carmen92126]

Is there a function that will query a stepper-motor indexer. I'm connecting LabVIEW to a Parker Computmotor, Microstep Drive, AX Series indexer via the RS232 connection. I think that LabVIEW will need to query at a frequency of about 10 Hz. But I don't know what function to use.

My general plan is to have LabVIEW ask the indexer "what angle are you at?" or "what step are you on?" every 0.1 seconds. With the reply data from the indexer, LabVIEW can calculate the angular velocity based on the 12,800 steps per revolution and time difference between steps. From there, to calculate my linear velocity based on (radius)*(angular velocity).

Thanks.

[Carmen92126]

Or, instead of having LabVIEW ask the indexer every tenth of a second, maybe there is a way to get the indexer to automatically say to LabVIEW "I have changed to a new position. My new position is XXXXX."  Then nothing would be communicated unless something changed.

I'm reading all the stuff under GPIB and VISA. I think it is somewhere in there.

[RavensFan]

Duplicate Post.

Why ask the question again?  You were already being helped in the other thread.

[Carmen92126]

Sorry if this was a faux pas to duplicate a question. I thought that "Query stepper-motor indexer" really gets to the core of my problem rather than "linear velocity". I was concerned that the title of my question no longer addressed what my need is.

Thanks for your help. I'll check the links you posted tomorrow. I also found the manufacturers' manual for the indexer. It has a section on communicating through the RS-232 ports (something I've never done). I'm going to read that next. I spent today reading about VISA and GPIB in LabVIEW help.

If there is a way to "manage" my discussions to edit out the fluff and wrong turns I'd like to do that. When the next person with the question comes along they would get a streamlined answer.

Thanks everyone for helping.