Web server logging option greyed out

[cktce]

I'm using a NI PXI-8108 controller with labview real-time to serve remote front panels to two laptops simultaneously.  The remote front panels were working fine for one and a half months, but three times over the past week the remote front panel on one and sometimes both laptops displayed a white screen that said "Remote panel connection is closed."  Refreshing the screen would restore the remote front panel, so it appears the network connection is temporarily dropping.

I'd like to start using the web server's log files, however the option to enable logging is greyed out on the PXI-8108 controller.  Is there a way to enable logging, or is it not supported on real-time systems?

[PatJamSim]

Hello cktce,

What options menu are you acessing to set the web server to log files?  You can right-click on the RT Target in your LabVIEW project and select Properties>Web Server.  When I do this, the option is also grayed out on my system.  You can also navigate to Tools>Options>Web Server to configure the host's web server.  On my system, this check box is only accessible when you also select Enable Remote Panel Server.  Are you able to adjust the setting of your host, or is logging already enabled?

I know that you can set the web server log to be active programmatically using property nodes.  See the following link:

http://zone.ni.com/reference/en-XX/help/371361J-01/lvprop/app_web_srvlog_enbld/

The information page says that this property node is available in real-time systems, but I am not able to verify that it will activate logging on a PXI system.  It is possible that this setting will have no effect on the RTOS, and the property node will effectively do nothing.  I have put an information request in to R&D about the usability of this feature on a real-time PXI system, but there is no set time table for when I will receive a response.  I will update this forum when I have more information.  

Please let me know if you are able to activate logging, whether manually or programmatically.  Thank you.

Regards

[cktce]

Hi PatJamSim, I tried to enable the web server log files through the RT Target. I am able to enable web server logging on the host, but no new log files are created, I imagine because I'm using the web server on the RT target vice on the host. I tried to enable the web server logs programatically using the property nodes you provided, however I wasn't able to get it to work. No log file was created in the path I specified on the RT target. I did notice something weird while trying to get it to work that makes me think logging isn't supported. I used the property node to also display the log file path on a front panel indicator When I ran the program through the project, the returned log file path was missing the last two letters of the path I specified, even when I shortened the specified path. When run as a startup application on the RT target, the returned log file path was empty. Please let me know what you find out from R&D, or if you have any other suggestions I can try. Thanks!

[PatJamSim]

Hello cktce,

I had the chance to communicate with R&D and was informed that real-time targets do not have the functionality to capture the web log.  As such, I have a few suggestions for other ways to implement target monitoring.

From your original post, I inferred that you are monitoring a single target on two hosts.  The web interface is typically intended for use when a higher number of hosts need access to information from a single target.  Performance of a web service is typically worse than an architected host VI.  I would recommend building an executable VI that monitors the information from the target and displays or logs that information as needed.  If you are using network-published shared variables, then the same monitoring VI will be able to run on multiple hosts because those variables are available publicly over your network.  You will have to make sure the variables are only deployed and hosted one time by a single machine.  The architecture of the monitoring VI is highly dependent on the information you are monitoring from the target.  If all the information is network published, you should not have any problems accessing it from multiple hosts.  If this is not the case, you may have to set up a single host machine that collects all the data from the target, then shares the data over to the other host machine.  There are many possibilities for host interface.

I understand that you have already implemented a remote front panel interface and have been using it for some time; as such, you may not be able to completely modify your project at this time.  Hopefully you can find a method that works for you without failing intermittently. 

Regards,

[cktce]

Thanks for getting back to me, PatJamSim.

We had considered using an executable VI on the host, but a previous project using that setup had problems with randomly locking up.  We weren't using a real-time target on that system, so that could have been part of the problem, but at the time we attributed it to something going on in the Windows OS.  For this project we tried to minimize use of Windows to prevent similar occurences, but next time we'll keep your suggestion in mind (we can't make that big of change at this time).

In the meantime we'll use the laptop's logs to get an idea of what's happening.  Thanks for your help!