Digital output from USB 6008

[VeeJay]

Hi Guys,

I have a question regarding the NI USB 6008 DAQ. When it is connected to the USB, the outputs are pulled up to 5V. Is there any way to make the default to 0V. The 5V appear of the terminals when I measure then using a multimeter and this even when a program is not running on LabVIEW. Any help will not be appreciated.

ThankS!!!

VJ

[VeeJay]

Oops!! My bad... Any help WILL BE APPRECIATED.... i dunno why I put a Not there... 🙂

[Guruthilak]

In MAX right click on the USB device and select properties..See whether there any power up states and if ues write a value of "0"

Guru

[Dennis_Knutson]

The 6008 does not support programmable power up states.

[VeeJay]

@ Guru Thanks! Will check that out.

@Dennis, If it does not support any power up states, is there any way to make sure that the initial pull up to 5Vis negated and only when I require it programmatically, I could do it?

Thanks!

V

[Dennis_Knutson]

No programatic control means you cannot programatically change anything. As the manual states, on power up, the digital I/O is set to high impedance inputs. The pull-up resistor is internal. You could attach an external pull-down.

[VeeJay]

Ok. So, I can put a pull down resistor say 1k or 4.7k whatever from the digital I/O to ground. Correct me if I am wrong here. That would correct the initial state when it is high at 5V and before the program starts. But, when in a program I intend to drive a circuit from the Digital O/P, would it be able to drive it then?

Thanks!

V

[Dennis_Knutson]

No, not if you intend to use them as outputs. In that case, you would want to use an external inverter connected to the pins.

[VeeJay]

Yea! Just found that out on the website. THanks!

For others who may have similar questions, please follow this link for answers

http://digital.ni.com/public.nsf/allkb/B4FED0C879BD155F862569ED00142DC7