- From: Frank Mori Hess <fmhess_at_users.sourceforge.net>
- Date: Sun, 24 Nov 2002 10:13:42 -0600
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Sunday 24 November 2002 04:01 am, Fredrik Lingvall wrote: > Hi Frank! > > I have noticed that you have added an entry (ai_scan_up) for scanning > direction in the labpc_board struct for the lab-pc driver. However, > I still need to scan from highest to lowest channel on the DAQCard-1200, > that is, the chanlist must be in reverse order: Yes, I added that so the driver would reject chanlists that didn't count down in channels. The daqboard documentation says it can only count down (unlike the labpc-1200 for example which can also count up). > > I'm working on a small data aquisition toolbox for Matlab so I would like > be able to access all DAQ hardware suppored by comedi. Is it safe to > assume that all hardware are able to scan in reverse order or is there a > comedi function that can probe the scanning order of the device? No, a more common restriction is that the hardware can only count upwards in channels. Hardware-specific restrictions on chanlists are supposed to be caught by comedi_command_test() returning a 5. Not all drivers implement a check of their chanlists in their command tests though. The subdevice flags relevant to chanlists are the SDF_GROUND, SDF_COMMON, SDF_DIFF, and SDF_OTHER which indicate what analog references the subdevice supports (see comedi.h). - -- Frank -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (GNU/Linux) Comment: For info see http://www.gnupg.org iD8DBQE94Pq45vihyNWuA4URAuwkAJoCAUUgEJrmkxMvfbeVEHzV/bEnRgCfVysd W3dbwtwUI7O/Y0NGsP3wmDc= =L86G -----END PGP SIGNATURE-----
Received on 2002-11-24Z16:13:42