Writing to queues across applications...

[PA-Paul]

Hi All,

I have an application which I've written to control a measurement system, the main app is based on a kind of queue driven state machine. This application is typically built into an exe before use and then run from that. I now want to write a second application that can programmatically fire off some of the operations (states) within the first app. So, my question is, is it possible to do this using standard queues?

Simply put, I have a Queue (sink) in App 1, and I want to write things into that queue from App 2. (note, this is not VI 1 to VI 2, this is separate apps...).

Thanks in advance for any help!

Paul

[Antoine Chalons]

Hi All,

I have an application which I've written to control a measurement system, the main app is based on a kind of queue driven state machine. This application is typically built into an exe before use and then run from that. I now want to write a second application that can programmatically fire off some of the operations (states) within the first app. So, my question is, is it possible to do this using standard queues?

Simply put, I have a Queue (sink) in App 1, and I want to write things into that queue from App 2. (note, this is not VI 1 to VI 2, this is separate apps...).

Thanks in advance for any help!

Paul

Yes, you can do that.

I posted an example a while ago, it was in LV 8.20 if I remember well.

See here, and this thread can be interesting too.

The example was with FGVs I believe, I also have one with Queues somewhere... (maybe).

hope this helps

The example was with FGVs I believe, I also have one with Queues somewhere... (maybe).

There it was!

partager une FGV (queue).zip

[PA-Paul]

Hi Antoine,

Thanks for the reply. I'm still trying to get my head round it all. I've done lots of labviewing -although not perhaps by people here's standards - but never really got into using VI server like this! I ran your example fine using the exes, but when I ran it directly from the VIs in projects, I get an error when I try to run "B"... I get error 63 - serial buffer overflow. Any idea why?

[PA-Paul]

Never mind - got it. I had to set the port number within the project file (A).

Thanks again!

[viSci]

Also worth mentioning is that in LV2010 we now have 'Network Streams' which function like lossless network queues between any processes.

[rkanders]

Asynchronous Message Communication (AMC) Reference Library

http://zone.ni.com/devzone/cda/epd/p/id/6091

LabVIEW Simple Messaging Reference Library (STM)

http://zone.ni.com/devzone/cda/tut/p/id/4095

[Antoine Chalons]

Thanks again!

Glad it helps!

Never mind - got it. I had to set the port number within the project file (A).

Yes, all the VIServer parameters need to be carefully set, that's what took me the longest to figure out.

Also as sachsm pointed out this is sort of an "old" way, I used it from LV 6.1 to LV 8.6 (and it might even work with older versions) but with newer versions you certainly have new ways.

[PA-Paul]

Thanks for all the info. I do have LV2010 still sitting in its wrapper on my desk... unfortunately, this project needs to stay LV 8.6 compatible for a while... customers eh? Who needs them?!