CVT Client Communication (CCC)

[annacm]

That is actually very helpful.  You've saved me a lot of time.  It was the answer I was expecting but hoping not to hear.  The CCC was implemented early on in this project, which has experienced significant scope creep, and I knew I must be getting close to the limits of both my cDAQ and my communication method.  I like the idea of splitting up my high-speed data from the rest of the information I'm passing up.  Been meaning to come up to speed on network streams anyway, so I guess it's time to dive in!  Thanks!

[carrasquel]

Hello, Whit the CCC library, is there any limit in the number fot tags to sync within a CCC Server and a CCC Client?... I working on a project with 250 tags but it seems that the CCC Client can not connect, because it goes timeout, thanks

[BeCeGa]

Hi carrasquel, what dataytpe are the tags? also how long is the name of the Tags? And how fast are you updating the Tags?

Best Regards

[Dave_Thomson]

   I'm running into the same issue that StevePVI reported in 2010. I need to create an application where the client and server can become disconnected/reconnected or stopped/restarted and always reconnect the CCC. I've got version 3.0.3.9 installed in LV15. I finally found the "CCC Client Read" that Steve refers to, but I haven't yet found where it is called. I wonder if the code has been refactored since then. And it does have a "Force Configure?" input, so it would appear that the CCC library has been fixed to address this. But I'm not having any luck getting it to work.

    I configure the CCC server on the RT. I connect from the Host. Things work. I unplug the ethernet cable. Things stop working. When I plug it in, my code tries to do a Client Synchronize. On error, it does a Client Close and then tries to reconnect with a Client Init. But inside the Client Init, the STM VI "Read Meta Data" times out after 25 seconds.

    Are there any recommendations on how to get CCC to reconnect after a network break, using the current version?
Thanks,

     DaveT

[xl600]

My memory has faded a bit on my posts about CCC, but I recall havign fixed an issue in the CCC server concerning the basic mechanism used to reconnect.  This was focused on the ability to run multiple CCC servers at the same time while allowing disconnect and reconnects.  I uploaded a version here.  Perhaps that might be helpful for your issue?

[Dave_Thomson]

Thanks for the suggestion. I downloaded that and was getting ready to try it, and for some reason, it seems to be reconnecting just fine now. I'm not sure what I did differently. In any case, perhaps the changes you made HAVE been put into the official package by now.

DaveT

[xl600]

When I get back into working my project, I will download the latest CCC and check.  I didn't upload anything to the official github group so it'll be a nice surprise if the issue was fixed regardless.

[Sabo]

This is a reply to message 11 concerning "resolve remote address (T) flag.

This change seems not to be implemented in the newest NI CVT Client Communication (CCC) version 3.0.3.9 in the VIP. Could someone responsible please update the package?

[Sabo]

<consolidated response above>

[SISUSarci1]

I'm having a similar issue to Dave with regards to reconnecting. On RT I manually disconnect and reconnect the server (for testing purposes). On my Host I'm watching for drops in the connection and then attempting to reconnect for a period of time. The problem is that 80% of the time after a disconnect and reconnect on RT I cannot reconnect on the Host and always get error 56 back from my Client Init. I have put together a simplified example project to demonstrate (attached). My question is, what is the proper way of reconnecting to a remote server after the remote server has been restarted?

To test, run the RT code on a RT controller interactively (though it may work on the same pc). Start the Host code and select the Connect switch. Adjust the Example In and Example Out  switches to demonstrate proper communication. On the RT code, set the CCC Wait (ms) control to some amount of time (I've made it anywhere from 100 ms - 2000 ms), then select the Interrupt CVT boolean. On the Host control, note that it disconnects and attempts to reconnect. 80% of the time it cannot reconnect and every retry fails with error 56. If you don't see the error on the first attempt select the Interrupt CVT boolean on the RT code a few more times to see it happen.