Re: Digital Input reading problem for PCI-1762

On 03/11/06 16:33, Navneet Kataria wrote:
> Hello,
> 
> I am using the comedi driver version 0.7.70 and comedi
> library version 0.7.22 for interacting with pci 1762
> device. The digital output subdevice(1) is working
> perfectly but i am facing problem reading digital
> inputs.
> 
> I have using voltage source of 12 V as input. The
> problem is the when i run 
> $ inp -s0 -c0 -f/dev/comedi0
> for reading the input value, it always shows it 1. I
> mean even if I disconnect the power supply. Similarly
> for other channels (some garbage 0/1 pattern
> irrespective of attached input source). 
> I had testing the board successfully in windows OS
> where the results are perfect.
> 
> I had used inp program(given in comedilib distribution) for reading digital 
> as well as contact inputs for the device pci1733. So it seems
> that the library routine is fine.
> 
> Can you guide me to solve this issue ?

Digital inputs are usually 5V TTL level.  Are you sure you haven't
damaged the inputs by connecting 12V?  What does the input read if you
connect it to 0V?

-- 
-=( Ian Abbott _at_ MEV Ltd.    E-mail: <abbotti_at_mev.co.uk>        )=-
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Received on 2006-11-03Z15:21:19