Visa Read Issue Code -1073807253 - myRIO - PmodGPS

[Dennis_Knutson]

So, have you added back the command to change to a 10 Hz rate? Originally, you had it with the incorrect termination and I don't know if you've tried out again.

[cwestfall]

I had originally found these PMTK codes and couldn't get anything to work. That is when I posted up the codes yesterday.

I took your advice and went back to what I was doing but modifed the code with the proper commnands (\r\n) and it appears to be working!!!

I attached the Main.vi file for anyone who wants to use it.  Thank you again Dennis. I owe you one!

[cwestfall]

Here is a screen shot if you don't want to open the vi file

[cwestfall]

So, it looks like I spoke too soon. This only works if the GPS isn't locked on. As soon as it locks on, I get the same code (1073807253) or I get (1073807298)

I did search what the 1073807298 was and it sounds like I need a higher Baud rate. When I bump it up, i get the 1073807253 error again.

Any ideas?

This is really discouraging. I have probably 40 hours in debugging this. 

[cwestfall]

Anyone have any ideas?

[Dennis_Knutson]

In the small manual that you attached, there is no mention of anything changing once a lock is obtained. I would suggest contacting the vendor. One thing to try on your code is to wait until lock before changing the baud rate and sample interval.

[cwestfall]

You mention wait until lock. Are you talking about locking onto the gps cordinates?

How would I exicute that within the look? Just wire it before the read VISA  (loop with a wait 1000 ms?) in series between the loop and the read?

how do you code a wait until lock?

thanks for the help,

[Dennis_Knutson]

You are the one that said you get an error once the gps is locked on. You are the one that posted a video with a VI that reported the lock status. You can add a loop with the default settings at the very beginning and exit when lock is achieved. Then your code with the baud rate, etc.

Note that I have no idea whether this will make a difference. The data sheet refers to the vendor of the gps module and a more complete manual.

[cwestfall]

yeah, I have reached out to the mfg a few times in the past couple of weeks. They are in the UK and seem unable to return an e-mail or phone call. 

I guess I'm just going to find a different GPS unit. So, annoying, but I need to get this braking test finished.

Do you have any suggestions on a good GPS unit that will work at 10 hz or higher? I know there are a ton of units that will do it, I'm just looking for some first hand experience. 

[dkfire]

There is at least one problem with your current code.

You have a Wait(ms) in the code with a value of 100ms.

This will force your loop to only iterate 1 time every 100ms, give a 10Hz loop frequency.

As you are only reading 1 line pr loop iteration, then you are about 5 line behind for every loop.

You will get error as you are not reading the serial buffer fast enough.

You need to loose the wait to be able to follow up with the GPS. The GPS is sending 5 lines at the minimum every 100ms at the 10Hz frequency.