Real-Time Measurement and Control

[MartinP]

I have connected a cRIO-9073 to my computer, and connected into my LabVIEW project. I have downloaded software to it, and set it up for Scan mode. Problem is, every time I connect to it in LabVIEW, it disconnects after 3 minutes exactly. I haven't done anything at all with it, so it runs no program or anything. Is there some software it is missing, or is there some configuration detail I'm missing, or what can this be ?

Martin

[MartinP · Accepted solution]

I found the solution to the problem.

When I format and install software on the cRIO-9073 from a computer win Win-7 (64 bit) the communication problem is present. When I install the same software from a computer with Win-XP (32-bit), the problem is gone. The problem is reproducible.

Martin

[TutuAjayi]

I have the same 9073 hardware, LabVIEW 2011 and NI-RIO 4.0 running on Windows 7. I am not able to reproduce the problem.

I did notice that after I installed all available software (Selecting all of the Add-ons), the cRIO controller is only left with about 5MB of memory before even opening LabVIEW.

This is in contrast with to 40MB when i install only the minimum).

I wouldn't be suprised if the system stability issue you experienced is due to the small amount of memory available. You can try installing less/unneeded software. 

[A_Person]

Hi Martin:

I think adecold is probably onto the answer.  Can you specify which version of LabVIEW Real-Time and NI-RIO you're installing and which Recommended Software Set (RSS) you're selecting (I'm assuming the option that includes Scan Engine Support)?  Depending on the version of LabVIEW you're using, I would recommend upgrading to NI-RIO 4.0, installing the RSS, and then only selecting the add-ons you need for your application.  This should keep memory usage to a minimum.  If you can't or don't want to upgrade the NI-RIO driver, I would recommend using the minimal RSS install and then using the custom install to add Scan Engine Support and leaving everything else off.

[DNgineer87]

I am having a similar problem even with XP.  When we try to write data to the on-board memory it seems to end-up in RAM instead.  Once the RAM is full we loose connection with the cRIO.

My understanding is that "The cRIO-9073 features 64 MB of DRAM for embedded operation and 128 MB of nonvolatile memory for data logging."  We are running in scan mode, and our VI writes data to the virtual c:\ drive.  We wrote the simplest data logging routine we could, to minimize RAM required - no arrays, no local variables.  Yet when we run the vi and monitor the RAM it increases continually as the vi runs.  When we check the c:\drive the data is there.

Why is my RAM filling up?  Could it have something to do with scan-mode and the shared variables required to read a given channel?

[TutuAjayi]

The host (windows) OS has nothing to do with what's installed to the target.

I'm not expert on data acquisition and logging but here are some tips you can try

1. In MAX, do a custom install, be sure to only install components that are necessary for your application. That should be NI-RIO, LabVIEW, Scan Engine, and a few other things. Disable all of the web stuff if you don't need it. This should ensure there's a little more RAM available.

2. Deploy only the RT Scan engine variables you need

3. Be sure to flush all disk buffers.

3. You can launch or install the NI Real-time Excutin trace toolkit to carefully analyze your RT resource usage

[Kirst]

Try upgrade NI-TimeSync.

http://joule.ni.com/nidu/cds/view/p/id/2819/lang/en