Motion Control

[Frank V.]

I want to have the value of the coarse update rate in ms or microseconds in the CLX. I checked if I could call this value by using the GSV-instructions and did not find it.

I have motiongroup updated on coarse update rate and a motiontask triggered by the event of motiongroup updated. To find a good balance

on the processor CLX execution time of the (1) motiongroup update rate itself and (2) the motion task which is logic with motion instructions, I would like to have the value called by the CLX .

If possible I would also like to know if I can change the coarse update rate with a SSV, to find a better balance between both points mentioned both.

Regards,

FV

[fuzzy_logic · Accepted solution]

I have searched what you need...It isn't available in GSV or SSV instructions and also I've not found indication about a Generic CIP message that could retrive it... it seems not possible to me

- fuzzy logic

[NorwichUK]

It is possible via a generic CIP message, the target of this message needs to be the processor that owns the particular Sercos card that you are interested in.

[fuzzy_logic]

May you post the Generic CIP configuration please ? I think this could be interesting for Forum users, as there aren't documents that report this possibility ...

Thanks,

- fuzzy logic

[NorwichUK]

Any one wants an ACD example of this MSG - drop me your e-mail and I'll send it.

[fuzzy_logic]

First of all, I would like to thank NorwichUK for sending me the example...

Just a note: this will get the Programmed Coarse Update Time, in order to retrieve the real-time Last or Maximum Coarse Update Time, refer to Aid 50617...

Also, unfortunately, the request done by the user who started the thread was to WRITE dinamically this value... so again my answer is that it seems not possible to me, unless NorwichUK has some other news for us...

- fuzzy logic

Message Edited by fuzzy logic on 03-30-2009 05:15 PM

[NorwichUK]

CUR can only be changed offline - so theirs no point looking for a programmed way to do this - code can't run offline . . . so dynamically changing this via code can't be done as has been reported.

This is still useful if you are computing cams etc and you want to make adjustments how long things take to start / complete (typically most things are 2 coarse updates out of date). If you have blocks of code you reuse often, your CUR may vary from 2 - 8ms depending on how many axis you have configured and its nice to know a way to retrieve the CUR for a generic purpose.

[NorwichUK]

Attached is how to get the coarse update rate - a little late now, but at the time attachments couldn't be added.

Note - this reads from the processor as it is the processor that holds the CUR (you can only have one motion group per processor, and don't necessirily have to have Sercos cards as the example shows).

For some reason (or the last time I looked) this isn't documented anywhere in any public manuals, or on the KB.

Credit must go here to the Rockwell tech Support guy (lets call him AG) who dug long and hard to get this information from somewhere a couple of years ago now.