- From: Andrés Cascallana Alvarez <acascallana_at_simulare.es>
- Date: Thu, 19 Feb 2004 13:33:08 +0100
Hello, I'm working on an application that needs to perform real time operations on every scan. I've managed to do that in kernel space (with the help of Joerg Biedermann) using the comedi_callback. The problem is that when the load on the system is high, the code in the callback function is delayed. This leads to AI_Overflow errors. Is it possible to perform real time processing using the daq timers instead of creating a rt thread that polls the card via comedi_data_read() calls? I'm using comedi-0.66 with real time support, rtl-3.2-pre3, comedilib-0.7.21 and a NI6052E card. What does real-time support means? Does it mean that the ISR is 'never' delayed, but I must provide some kind of real-time consumer to read the data and prevent overflow? If that is true, how can i accomplish that? There is another issue: The 6052E can sample at a maximum frequency of 333KS, but using comedi command i've only managed to adquire data on the 16 channels at 2500 Hz. I've disabled DMA on the driver, i suppose that it could be the reason behind that. Is that true? As you can see, i'm a bit confused. I've searched both the rtl and comedi mailing list archives, and couldn't find an answer to these questions. Any help would be greatly appreciated. Regards, Andrés
Received on 2004-02-19Z12:33:08