Logging data with Mux80
Posted 06 June 2012 - 10:24 AM
Posted 06 June 2012 - 01:38 PM
Posted 13 June 2012 - 07:17 AM
Posted 13 June 2012 - 08:32 AM
%Call eGet function to get TC voltage [Error(1,n) AIN48(1,n)] = ljud_eGet(ljHandle,LJ_ioGET_AIN,48,0,0); Error_Message(Error)What is it returning for the voltage? Is it giving an errorcode? What if you test with a basic channel like AIN1 right on the U6? What if you use a jumper to VS or GND rather than your signal?
Posted 13 June 2012 - 09:29 AM
Posted 13 June 2012 - 09:50 AM
[Error Temp] = ljud_TCVoltsToTemp(LJ_ttK,0.002,300,0) Error_Message(Error)
Posted 13 June 2012 - 09:59 AM
Posted 13 June 2012 - 02:22 PM
My understanding of the [Error(1,n) AIN48(1,n)] code is that you get two output matrices, the first is an error check and should be a value of zero throughout, the second is the AIN value. This was the code I received from your file so I presume it is a check to ensure there is nothing wrong with the system.
When running your test code, I receive the following:
>> [Error Temp] = ljud_TCVoltsToTemp(LJ_ttK,0.002,300,0)
??? Error using ==> ljud_TCVoltsToTemp
Too many output arguments.
I also had an issue when attempting to load my directory which I have not had before the error is:
Warning: Directory access failure:
> In path at 110
In addpath at 87
In ljud_LoadDriver at 11
Could my issue be related to the directory path rather than the actual code? I tried to rectify this last night but was unable to make any progress.
For the directory issue, try specifying the full path where the header file exists, i.e. C:\program files\Labjack, etc. If it's a 64-bit machine that might be C:\program files (x86)\labjack\, etc.
It looks like the other error might be a bug in our code. If you look in the MATLAB_LJUD folder, and go to the functions, you will see a file called ljud_TCVoltsToTemp.m. I believe that file should read:
function [ljError, pTCTempK] = ljud_TCVoltsToTemp(TCType, TCVolts, CJTempK,pTCTempK) [ljError, pTCTempK] = calllib('labjackud','TCVoltsToTemp',TCType, TCVolts, CJTempK,pTCTempK)
function [ljError] = ljud_TCVoltsToTemp(TCType, TCVolts, CJTempK,pTCTempK) [ljError] = calllib('labjackud','TCVoltsToTemp',TCType, TCVolts, CJTempK,pTCTempK)
I think making that change to the .m file will fix this.
Posted 13 June 2012 - 06:05 PM
Posted 28 June 2012 - 01:01 PM
Posted 29 June 2012 - 10:31 AM
Posted 03 July 2012 - 08:14 AM
Posted 03 July 2012 - 09:37 AM
For the U6, 1k is fine for all gain/resolution combinations.
Your reading of the negative rail voltage with nothing connected is not unusual, and floating readings are generally meaningless:
However, when you connect your divider resistors with no signal connected to them, you essentially have just connected the AIN to ground with 1800 ohms. That should read pretty close to 0. Your readings do not seem right.
If you just use AIN0-AIN3 on the U6 itself, without the Mux80, do you see any of these problems? Do you see these same readings in LJLogUD? Does it depend on the order of the channels?
Posted 03 July 2012 - 10:39 AM
Posted 03 July 2012 - 11:07 AM
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