- From: Ian Abbott <abbotti_at_mev.co.uk>
- Date: Fri, 11 Aug 2006 11:15:57 +0100
On 10/08/2006 16:54, David Smoot wrote: > I'm pulling myself up the learning curve for Comedi reading the > documentation and the demo programs. I'm stuck finding the meaning of > CR_INVERT flag. It is used in one of the demo programs, receiver.c: > (the comments are mine as I try to grasp the program. > > cmd->scan_begin_src = TRIG_EXT; //Start a scan from an external trigger > cmd->scan_begin_arg = CR_EDGE | CR_INVERT | pin_clk; // > > pin_clk is the pin for the external trigger, CR_EDGE is self explanatory > (I think). Does CR_INVERT mean it triggers only on falling edge? Yes, that is the intended meaning when combined with CR_EDGE. Some drivers ignore the CR_EDGE and/or CR_INVERT flags if they only support a limited form of external triggering anyway. -- -=( 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 2006-08-11Z09:15:57