Can two different applications access one field point module on different channels at the same time?

[Aaron_G]

Yes, however there is a restriction in that only one IAK file can be active on a computer at a time. Thus both applications, which are calling into the FieldPoint Server, must be using the same configuration file. If the second one tries to use a different file, it will just be ignored.

Regards,
Aaron

[JimN]

Aaron G wrote: Yes, however there is a restriction in that only one IAK file can be active on a computer at a time. Thus both applications, which are calling into the FieldPoint Server, must be using the same configuration file. If the second one tries to use a different file, it will just be ignored. I have two different applications on the same computer, both use the same IAK file. I open one and start it running and it works fine. As soon as I start the second one the first one stops acquiring data. Only one or the other will acquire data at the same time. Both use the same (and only) IAK file. I am accessing channel 0-2 of an FP-120C with one program and trying to access channels 3-4 with the other program. One of your sales reps sent me this email regarding the same question, but I didn't quite understand and they didn't elaborate further >>"We briefly spoke about using a single FieldPoint system to control 2 different applications. Yes, you can use the same FP system to run 2 different applications. It's a matter of software programming and identifying the channels in MAX so you don't get lost when you program it in LabVIEW. Make sure you name the channels in MAX, something like channel 1 system 1, even though, it's actually pin assigned to channel 7. "<< Thanks Jim

[Sean_C.]

Hi Jim,

You should be able to acquire different channels on the same FieldPoint system from different applications.  What happens when the first application stops working?  Do you receive an error?  Does the program hang?  Does the same behavior occur if you start the applications in a different order?

Please reply back to these questions and I will be glad to help you troubleshoot this issue.

Regards,

Sean C.

[JimN]

The message reads: Error -33811 occurred at Unable to bind to the COM port. Another application is already using the COM port. :FP Read.vi Possible reason(s): Fieldpoint: Unable to bind to the COM port. Another application is already using the COM port. Thanks Jim

[Henrik_Volkers]

How about writing one (background) fpserver.vi, that is doing the connection to FP and use named queus ( or LV2 Globals or... ) to serve your applications?

Using VI server vis, every application look for that fpserver.vi and if not already up and running it fires it.

[Sean_C.]

Hi Jim,

Please take a look at the following Knowledge Base:

http://digital.ni.com/public.nsf/websearch/8F84131312800F4F86256DC60070EFBD?OpenDocument

This indicates that is it possible to have multiple LabVIEW applications or OPC Clients simultaneously accessing a serial FieldPoint Controller.  What API are you using to write this FieldPoint code?  Do you have anything else accessing the FieldPoint bank (such as MAX) when you get this error?

Regards,

Sean C.

[JimN]

I saw this knowledge base, and it says they can but it doesn't say how. I write the programs in labview, build with labview application builder. I open one program and start it running. As soon as I open a second program, the first one stops running and I get the error. The second program runs ok. It goes back and forth which ever program is opened last has priority. Nothing else is running. Jim

[Sean_C.]

Hello Jim,

Have you tried running the 2 programs as VIs rather than executables?  See if that makes any difference.  If not, please attach your exe's and I will try to reproduce this issue.

Regards,

Sean C.

[JimN]

I tried several times to attach the files, both must be too large.

Jim