usb-6008 toggle i/o line

[ajmartin]

I am using Labview 8.6 , measuring the temperture of a temperture IC and displaying the result in degree F and C, then writing the result to a measurment file if the result exceeds a limit I set in a compare function. I would like to also use the output of the compare function to change the state of a digutal i/o line to engage a solid state relay. My limited experience so far in controling the i/o lines is with DAQassist, I cant get get DAQassist to work in this situation. I have tried to convert the dynamic data type to something DAQassist would like to no avail. How can I directly control one i/o line to change state based on the output of a compare function.

Thanks!

Alan

[Dennis_Knutson]

The output of a compare is a Boolean. If the output of your comparison is dynamic data, change it with the convert From Dynamic Data function. Dynamic data is evil!

A Boolean is easily wired to a DAQmx Write function. The DAQ Assistant is not really required for something so simple but if you insist, I think that all you need to do is wire a build array function between the Boolean and the DAQ Assistant.

[ajmartin]

Thanks, I want this to be as simple as possible so I would rather not use DAQAssist.  I have searched for another way to do this from the functions on the block diagram, can you point me to where I might find a write to DAQ function. As you can see I am rather new to Labview, I have finished  the getting started with Labview book and am reading other material, but all the examples so far are using DAQassist. Any further help will be welcome!

Alan

[Dennis_Knutson]

I'm not sure what you mean about the examples. None of the examples that come with LabVIEW (Help>find Examples) use the DAQ Assistant. Look at Hardware Input and Output>DAQmx>Digital Generation. The simplest examples are Write Dig Chan and Write Dig Port. What you need is even simpler. All you need is a DAQmx Create Channel and a DAQmx Write set for Digital>Single Sample>Single Channel>Boolean.

All of the functions are on the Measurement I/O palette.

[ajmartin]

Thanks, I have a better idea of where to look now. What I meant by "examples"  was every reference to  i/o I have seen so far has used the DAQassist for i/o. And I have used these examples to do things like read a temperature chip and turn on LEDs but no example of talking direct to the lines on the port with out using the assist. I will look closer at the Measurment i/o palette.

[Dennis_Knutson]

I really have no idea what references you mean. As I said, the examples that come with LabVIEW do not use the DAQ Assistant.

[ajmartin]

Ok at the risk of beating a dead horse here I will try to clairify what I was talking about  "Examples" and "references" in relation to DAQAssist.  I thought it would be a good start in learning LabVIEW to read the publication that came with my Software "Getting Started with LabVIEW" by National Instruments.  In this publication the examples and references to turning on Led's and out putting Analog signals use the DAQassist and no examples of i/o with out it. I also downloaded the 6 hour hands on publication from National Instruments, same thing. So as I hope you can see I am trying to learn and have read both publications before turning here. I hope this clears up what I meant when I was speaking of examples and references. (in the publications)

Thanks for taking time to help, when I get back to my breadboard that I have the USB-6008 tied to I will try the things you have suggested

Alan

[Dennis_Knutson]

Okay, I understand. It's been a long time since I've had a need for a Getting Started guide.