- From: Luc Lefebvre <luc.lefebvre_at_mcgill.ca>
- Date: Thu, 15 May 2003 10:41:25 -0400 (EDT)
Hi, I am using libcomedi 0.7.19-cvs and have been experimenting with streaming input as found in demo/cmd.c. I have a NI-DAQ-Card 6062E <pcmcia> and am running kernel 2.4.18 and Debian Woody. Running the cmd as is produces the expected output, 1000 scans of 2048 <ie. inputs grounded>. The DAQ in question has an 8k buffer, 1000 scans * 4 channels = 8kbytes. I tried cmd -N 2000 and I get 1024 scans of 65535 <mostly> and 0 <some>, followed by the expected 2048. I did the same for cmd -N 4000 and I get 3072 scans of the 0xffff <mostly> and 0x0000 <some>. I then added "ret = comedi_poll(dev, subdevice)" after line 140 <the while = 1 line....>. I recompiled cmd and ran cmd -N 4000 again, this changed the pattern of 0xffff where I get three pockets of 128 scans of 0xffff <with some 0x0000 sprinkled in> in the 4000 scans. Any ideas or suggestions as to what may be causing this and what can be done about it? Am I misunderstanding something? tia -- Luc Lefebvre In the beginner's mind there are many possibilities, in the expert's mind there are few. <Shunryu Suzuki> Key fingerprint = D2E5 5E35 B910 6F4E 0242 EC63 0FD9 96D0 C7F4 784E
Received on 2003-05-15Z13:41:25