- From: Heinrich du Toit <heinrichdt_at_tlabs.ac.za>
- Date: Mon, 17 Sep 2007 09:05:52 +0200
Send me what you have so far - like the 2 seperate programs. Comedi and DAQmxBase code are just about 100% different. So there is really no point in giving you DAQmxBase code if you want to work with comedi. DAQmxBase is a pain - I had to install SuSE just for that - and SuSE is even worse. I haven't done simultaneous read/write in comedi yet. Will do that some time in the future - can't say when - but it needs doing. The way I understand it: There is atleast 2 sub devices - 1 for analog out and 1 for analog in. So you will need 2 comedi_cmd_struct's filled. One for the analog output and 1 for the analog input. Then I suggest running comedi_command_test with on both of these cmd struct's. - just to make sure. Then you need to start both commands with comedi_command. Now here is where I'm not sure how things are suppose to work. Either you can just directly read/write to the comedi dev (using write(comedi_fileno(dev), ect ... and read(comedi_fileno(dev), ect ... But I'm not sure. It should work If I understand this correctly: http://www.comedi.org/doc/r6162.html use comedi_find_subdevice_by_type to get the 2 different subdevice numbers for the 2 different commands your running. ok that's about as usefull as I can try and be On Mon, 2007-09-17 at 08:44 +0200, JUSTIN ABRAHAM wrote: > i'm running in a linux enviroment. i downloaded the DAQmxBase for linux from the ni website. i had problems trying to install it. i think its because i'm using SIDUX and the DAQmxBase is made for Mandrivia/RedHat/SUSE?? > > so i had a go at comedilib and its working well... besides the whole simultaneous read/write thing. i tested the ao_waveform and ai_waveform separately and they are working fine. i'm pretty sure the card supports simultaneous read/write. i downloaded the mailbox archive and found a guy that said he was able to simultaneously read/write with the same card (NI PCI-MIO-16E1). tried mailing him... no reply... the post was made in 2001, so there's a good chance he's contact info has changed etc... > > is there some way you could provide with some example code that you used to read/write simultaneously.... i need some direction... > > >>> Heinrich du Toit <heinrichdt_at_tlabs.ac.za> 09/17/07 7:47 AM >>> > Hi > > I'm unsure what the limitations of the Comedi drivers are. > > But I've used NI cards unders the NI DAQmxBase drivers from NI. > There where many different limitations. > > I was able to do analog read/write at the same time with an NI-6229 > card. So I had a waveform output on 2 channels and read them back in 2 > other channels :) > Not sure if your card supports this. > But there is no way to sync the 2 processes. > > NI has some fairly weird limitations inside. Some hardware some > software. So I'm unsure of Comedi. > > Do you have the windows measurement studio software? Maybe first check > if that can do what you want? Maybe your card doesn't support it. > > Further I suggest first testing ao waveform and then ai waveform > seperately. > > btw. You will need to seperate cmd's in your comedi program if this is 2 > work.
Received on 2007-09-17Z06:05:52