- From: Ian Abbott <abbotti_at_mev.co.uk>
- Date: Wed, 17 Aug 2005 11:43:29 +0100
On 15/08/2005 15:10, SA wrote: > Dear List, > > On my pci-das4020/12 card I have a puzzling problem, the board has a 8255 on > it for DIOs. I can successfully write to all channels (0-23, ports a,b,c), > however, I cannot read from ports B and C (channels 8-23). Strange. Are you using comedi_dio_config() correctly? Does the board work okay with Measurement Computing's software? Note that the 8255 driver configures all the channels as inputs initially, so if nothing has ever configured them as outputs since the comedi device was configured, they should remain configured as inputs. > The channels in ports B+C all return 1 regardless of input, does anyone have > any suggestions? because I am quite stuck now. You have some of the > I presume that when you set the direction for one channel in a port then all > the other channels in that port also have their direction set- is this > correct? Yes, the channels are grouped 0-7, 8-15, 16-19 and 20-23. Configuring any channel in a group affects all channels in that group. -- -=( 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 2005-08-17Z09:43:29