Re: Digital Input reading problem for PCI-1762

On 04/11/2006 05:45, nkataria_at_npcil.co.in wrote:
> One more observation...i think this might be useful...
> When i run info program on the device, it gives me the following output....
> --------------------------------
> overall info:
>   version code: 0x000746
>   driver name: adv_pci_dio
>   board name: pci1762
>   number of subdevices: 3
> subdevice 0:
>   type: 3 (digital input)
>   number of channels: 16
>   max data value: 1
>   ranges:
>     all chans: [0,5]
>   command:
>     not supported
> subdevice 1:
>   type: 4 (digital output)
>   number of channels: 16
>   max data value: 1
>   ranges:
>     all chans: [0,5]
>   command:
>     not supported
> subdevice 2:
>   type: 3 (digital input)
>   number of channels: 4
>   max data value: 1
>   ranges:
>     all chans: [0,5]
>   command:
>     not supported
> --------------------------------
> 
> My query is when the card manual says that the digital input range is 10
> to 50 V -DC. Then why the info software says that for subdevice 0 -
> digital input the range is 0-5V ?
> Is this hard-coded info by card type or is retried from the card at
> run-time ?

It's a hard-coded value for digital input subdevices in Comedi.  It is 
possible to change the driver to report a different range, but it is 
pretty pointless.  The reported range is not very interesting for a 
digital input.

It looks like there some input circuitry on your card that converts the 
input range from the manual into the normal TTL logic level, so you 
won't have blown anything up by connecting 12V.

If you are still reading garbage from the input after connecting the 
input to 0V, then assuming the connections are correct, it suggests a 
bug in the driver.  The documented status of the driver is "untested", 
so perhaps the PCI-1762 has never been tested with this driver.

-- 
-=( Ian Abbott _at_ MEV Ltd.    E-mail: <abbotti_at_mev.co.uk>        )=-
-=( Tel: +44 (0)161 477 1898   FAX: +44 (0)161 718 3587         )=-

Received on 2006-11-06Z14:10:25