Visa Read Issue Code -1073807253 - myRIO - PmodGPS

[cwestfall]

I'm very new to LabVIEW. I'm a senior, so I have had two measurement classes that used data logging equipment. I have had my hand held twice creating new programs. I just bought my first myRIO and I'm trying to datalog gps at 10 hz.

With the help of a few on here, I have been able to switch the Baud rate (I believe) but now I'm getting the Visa read error code 1073807253

I have attached my full program, but below are screen shots of things I have changed. The initial program worked fine at 1 hz, so I know the problem isn't the code itself, but it relates to what I'm changing. I did a bunch of searching and I found this page http://digital.ni.com/public.nsf/allkb/F3E0621CB71AA16786256F970000FC57 that talked about adding a buffer in the system. 

I added the pause but that by itself didn't do anything. So, then I completed the modification and added the buffer.

That still resulted in the same error. After doing quite a bit of additional research, I found where someone said they just ignored the error. So, I gave that a shot and added an ignore error code.

Now the program runs without throwing up the error, but it isn't running correctly and it isn't running at 10hz. See the NMEA coded is it now displaying below.  

Anyone have any ideas? I'm really stuck on this one and I'm behind schedule on completing this project.  Any help is greatly appreciated!

[Dennis_Knutson]

Duplicate - http://forums.ni.com/t5/LabVIEW/Having-problems-changing-sample-rate-from-1-HZ-to-10-Hz-myRIO/m-p/30...

It's rude to duplicate threads.

You were already told that if you change the instrument's baud rate, you must reconfigure VISA. Why won't you do that? It's rude to ignore advice.

[cwestfall]

I have done everything you advised (that I am aware of). I have posted up everything I have done. I have repeatedly asked for additional guidance and haven't gotten anywhere.

I figued this was a different issue seeing as I have a VISA problem now. So, i posted a new thread.  I figured that once I came to a solution, I would post the solution on both threads.

What am I missing, what was the directive that I didn't do? I need help and don't really have a grasp on what or how everything works. 

[Dennis_Knutson]

As mentioned, you have to reconfigure VISA if you change the device's baud rate. Mentioned in both threads, as a matter of fact.

[cwestfall]

here is where the disconnect is.

How do I do that. I thought that was what the NI Max was for. But you said to ignore that. So, I don't know how.

[Dennis_Knutson]

No. In your code, do a VISA Close. Then do a VISA Configure Serial Port with the new baud rate.

I have some doubt whether this will change anything at all for the actual rate that you acquire samples. I suspect you will just get a single sample faster but the time between samples will remain the same.

[cwestfall]

Ok, So, I got ride of the buffer and error ignore and went back to what I was using before.

I added in the close and put in a new Visa Config. I connected the error out of the Visa close to the Error in of the Config. Do I need to do that?

As you expected, the time between samples is still 1 second. Thoughts?

[Dennis_Knutson]

I don't know how the time between samples can be increased, sorry. It might help if you can publish a link to the manual for the hardware.

Your original code had a command that you said was supposed to change the sample rate. You also said that was the reason you needed to change the basis rate.

[cwestfall]

Here is the reference manual. The codes are on the bottom right of page 2

https://www.digilentinc.com/Data/Products/PMOD-GPS/PmodGPS_rm.pdf

Here is a video walk through of the code I'm using.

https://www.youtube.com/watch?v=SebcpkbYBd4

[cwestfall]

Here is another PDF.