How do I increase the refresh rate provided by the Tag Engine?

[Kahless]

Good Day,

Part of an application I've designed reads in various analog inputs from various sources (3 serial, a handful from the NI-6229 and some temps from the USB-9211A).  My Labview software (LV v7.1) is set to read in the values at 8 Hz (every 125ms).  Though when running, the Tag Engine online provides updated information about once a second (for the both the NI inputs and the serial inputs which have been setup to be read throug the Tag Engine aswell).  When going in the tag configurator, the groups that the channels are part of is set up with "Update Rate (secs)" = 0.20s by default.  I don't even get that.  Just a bout once/sec.

I've tried looking through MAX a bit but can't seem to find anything there myself.

Any ideas would be much appreciated.

-

Sean

[unclebump]

Are you using the read tag or read multiple tags vi to get your data?? What is wired to the time interval on the read multiple tags?? It defaults to 1 second. Post your files.

[Kahless]

I'm currently just using read tag (not multiple).  (Somewhat new to Labview, didn't know of the read multiple at the time, which I have learned since then is 2 icons over :)).  Basically, tag constant connected to read tag, connected to indicator.  Channels have been calibrated in MAX to provide meaningful data (pressures, etc).  Unfortunately due to confidentiality reasons I can't post any files.

Aside from what I discribed in the previous post, does it sound like I missed anything in setting up the tags?

Message Edited by Kahless on 04-24-2006 07:35 AM

[Kahless]

To further discribe how the tags are setup, in both, Edit Tag->Operations->Engine AND Edit Tag->Connection-> Edit...(group) my deadband is set to 0.  The majority of my tags are going through the "National Instruments.LookoutOPCServer".

[Kahless]

I've also pulled up the tag monitor while the software is running and can see there that the Tag Engine appears to only be updating about 1/sec.

Any further ideas will be very much appreciated.

[Khalid]

If you're using Read tag VI, and haven't wired anything to the timeout input, what is the loop-rate for this piece of code?  That will determine how often you read the Engine.  You can set the loop rate to your desired rate and then observe the 'changed?' output (or the timestamps) to see if you're getting new/stale values. 

As for in Tag monitor, I don't think you can specify an update rate -- but you can try refreshing from the View menu. 

Finally, what is the poll-rate for the driver objects in Lookout?  This would determine when you actually acquire the data. 

Hope this helps.

-Khalid

[Kahless]

Nothing is wired to the timeout input.  It's read in a loop that repeats every 125ms (8 times / sec).  How do I check the poll rate for the driver objects in Lookout?

--

Sean

[Khalid]

So, when you read the tag in the loop, what do the timestamps say? 

I believe you're using the Lookout Protocol Drivers, right?  I don't have that right now, but you should be able to modify the Objects' properties (under "Modify" menu??).  Here will be the Poll field.  0:01 is one second.  0:0.1 is 1/10th of a second, and so on. 

Regards,

-Khalid

[Kahless]

Khalid,

Right at this time, I don't have the ability to throw an indicator into the code and run it to display as the stand is currently running clearing out a backlog that occurred over the last couple weeks.  That's why I had loaded the tag monitor while they run, and could see there that the values updated (and were timestamped) about every second.  I may try getting in there to accomplish what you suggest when they should be shutting down in about an hour and a half (if below doesn't work).  Does the tag monitor not update whenever there is a value change (and update the timestamp accordingly)?  That's what I understood from what I've read about it.

I think you may have pegged it though on how the server was configured.  I went into the server explorer and found a setting under LookoutOPCServer->Properties->Groups titled "Update Rate (msec)" which is currently set to 1000.  I'm going to try this out and will repost afterwards (hopefully when it works :)).

Thank you much (again) for your valueable time,
Sean

[Kahless]

Maybe I jumped the gun there.  I don't seem to be able to accomplishing anything useful in there.  Can create groups that disappear when I close the server explorer.  Wouldn't know what to do with these groups anyways.  They are not related to the I/O groups I have for my inputs.  Hmmmmmmm...