How do two fieldpoints with embedded VIs communicate with each other?

[Gizmaa]

How do I get two fieldpoints to communicate with each other?  I need cFP-2120's to communicate with other cFP-2120's and cFP-1808's all with embedded VIs.

My Setup:
cFP-2120
Software Installed
     DataSocket for LabVIEW Real-Time 4.4
     Fieldpoint Drivers 6.0.0
     Fieldpiont VI Manager 6.0.1
     LabVIEW Real-Time 8.2.1
     NI-Serial RT 3.3.2
     NI-VISA 4.3
     NI-Watchdog 2.1.5
Modules
     cFP-TC-120
     cFP-AI-112
     cFP-PWM-520

cFP-1808

[Gizmaa]

I was able to get the Datasocket method working.  It is a very slow method though.  I didn't check the exact run time but it was perceptible.  Are there any fast methods?  I will eventually need to collect a lot of data from a cFP-1808 and store/manipulate it in a cFP-2120.

An image and the VI are attached.

[Ben]

I'd advise an upgrade. The FP code from early version sof LV 8 has issues with the CPU being dominated by background processes.

Ben

[Gizmaa]

Are there any other functions that can query blocks from on a cFP-1808 from a cFP-2120 using compiled programs and no computer in the middle?  The other functions I've seen require some server function listening for a command.

Is there a way to use TCP or UDP to query modules on a cFP-1808?

[Kevin_S]

Hi Gizmaa,

You could use network-published variables along with this article (Methods for Binding a Shared Variable to a FieldPoint Channel) in order to access different channels.

Also, you could try using a TCP/IP connection since the Shared Variables are built upon this.  Using TCP/IP directly will allow you to communicate faster than through the use of Shared Variables.

I hope this helps,
Kevin S.
Applications Engineer
National Instruments

[Gizmaa]

I tried the first method outlined in the link you provided but I keep getting an error with the network-shared variable.  It returns a 0, an error code of -1950679034, and a source of ni_tagger_lv_Read.  A search of NI showed that this is likely due to a value not being received.  The variable information is correct since it's visible and updating in the Variable Manager.

What am I doing wrong?

Attached are my project files.

[nathand]

Perhaps I'm misunderstanding you, but you can do a FieldPoint Read of a remote module exactly the same way you read data from a local module.  The FieldPoint resource name includes the name of the controlling module, so you can have code running on one 2120 that reads from several other remote FieldPoint units using the standard FieldPoint Read function.  I've done this and it works fine.

[Gizmaa]

I have tried using the standard Fieldpoint Read/write functions but when I embed the program on a cFP-2120 the remote FP read/write functions do not work.

[nathand]

When you say "do not work" what error are you getting?  You probably need to make sure that the right IAK file (FieldPoint configuration) describing all of your FieldPoint modules is properly deployed to the FP-2120.  Unfortunately I can't give you an exact procedure as I no longer have any FieldPoint modules available, but I've done this in compiled applications and it worked as expected.

[Gizmaa]

I tried using the FP Open vi with only half success.  It worked on my computer but when I embedded it it did not do what it was intended to do.  The script I created checks the temperature of a thermocouple on a cFP-1808.  Depending on the temperature it lights a certain amount of LEDs.  When run from the project setup it returned the error " The specified tag name was not found. : FP Create Tag .vi", error code of 32812.  The .iak file was put in the root directory of the FP (C:\Mesocosm-01.iak).  When run on the computer I correct the .iak file location.

Attached are the necessary files.