How do you interface Labview to a 3rd party hardware. I have installed the drivers yet i still fail to pick it up. I've written code already but now need to test the actual parameters.

[*aza]

Aza

[Dave-C]

Hi Aza,

How are you physically connecting to the device?  For example, is the connection through USB, Serial, GPIB?  Knowing this will help with troubleshooting this issue.  

Also, are you familiar with Measurement and Automation Explorer (MAX)?  And, on that thought, is your issue the connection to the device, or the LabVIEW interface for connecting to the device?  If it's the LabVIEW interface, please post at least a screenshot of your block diagram so that we can see what you're doing with it.

Thanks,

-Dave C

[*aza]

The device is a microDAQlite USB hardware from Eagle Technology. Iam a new user of Labview. Iam not very familiar with MAX. 3 weeks back I came to NI offices in Midrand. I was told that the code would work. The problem I now have is connecting this hardware to Labview to acquire the actual parameter from the environment. On my code I generate values for pH and Temperature. These are the values i now want to acquire from the Environment. The DAQ assistant cannot recognise the hardware. How do i interface the hardware to my program. Iam only using this in the interim stage. Iam waiting for an order for the DAQ 6008.  

[Dave-C]

Hi Aza,

Thanks for putting up the code and for the further explanation.  It sounds like you have the right idea of trying to use DAQ Assistant in your code, I presume in place of the random number generation.  The hang up on this is going to be that DAQ Assistant uses the daqmx driver, which will not work with third party devices.  You can search ni.com/idnet for a driver set for your device, otherwise you'll need to use VISA commands to communicate with it.  There are VISA examples you can use as a starting point in the Example Finder that's included in LabVIEW.

Depending on how long it will be until you have the 6008, it may be easiest to wait on it, as the daqmx drivers will work with it and should implement rather easily.

Regards,

-Dave C

[*aza]

 Ill be in position of ny DAQ 6008 on Monday. It was delivered to a wrong receipient. As I mentioned earlier, I am still raw when it comes to programming in Labview. What tips can you give me when it comes to setting up the DAQ assistant. I cannot do it practically now since I dont have any hardware connected. My assumption is that ill need to configure it for  two channel analog Acquired signals. I want to have two outputs that will drive the alarms(generate signals). Can i merge the signals if any one of them is true then have a signal generated(alarm). How best do i tackel all of the above.

[Dave-C]

Hi Aza,

I know that setting up the Daq assistant can be a little intimidating when first starting out.  But after a few times doing it you'll be comfortable and know the settings that you're concerned with.  In the meantime, to get started I'd recommend this link to learn about the configuration environment for Daq Assistant.  

The Assistant will output a signal of Dynamic Data Typa (DDT).  What I would recommend for doing for an alarm would be to use the "Greater?" check node from the "Comparison" palette.  This will output a boolean value that work well for an alarm.  Since you're running multiple checks, I would recommend using the "Complex Arithmetic" function node from the "Boolean" palette if you're wanting to merge those signals to a single alarm.  I've attached an image that shows how I structured this.  That being said, there may well be some other methods to accomplish your end goal.

Good luck with your next steps!

-Dave C

[*aza]

Good day Dave.

 I got my DAQ 6008 . I have set up the Daq assistant to acquire the pH and the temperature.I forged the ph signal through custom scaling the same signal from the Lm35 wich iam using as a temperature sensor for the time being.From your attached program i am a bit on the dark as to what are you comparing. Where did you get those values? Sorry for asking so much.

Regards :Aza

[Jacob_K]

So the values coming from the DAQ assistants are just representations of any data and the constatns are just any numbers that I am comparing them against.  The code only represents a process of comparing not a particular comparison.

Jacob K

[*aza]

Good day once more. Kindly look at my attached picture. Iam trying to drive an output PO.O to generate 5 volts when the conditions are met, using the compound arithmetic as you suggested. I connected an LED to see the results.GND to terminal 32 of the DAQ 6008 and pin 17 to the other side of the LED. For most of the time the LED is on. It does not correspond to my alarms on the VI. What am I doing wrong ? 2.I finally got the pH transmitter 4-20mA. Ill connect a 250ohm resistor parallel to it to get voltage outputs  0-5V. Using my a look up table (with the temperature plz see  posted VI) i want to activate an external device by generating a high signal when my ammonia exceeds 1.  How do i achieve this?

[Dave-C]

Hello Aza,

I would recommend starting with moving your Daq Assistant outside of the Case structure and only passing it an array of true or false.  I created the array by right clicking the input terminal and selecting a constant.  I'd be curious if the current structure is causing a problem here, so please give this a try and let me know what happens and we'll go from there.

I've attached a screenshot of what my Digital Out Daq Assistant looks like.

Regards,

-Dave C