comedi supported low cpu load, continuous scan analog-in card?

Hallo,

I am looking for replacement of our old ISA-bus DataTranslation 
DT2831-G cards.

They had 16 12-bit analog-in channels multiplexed at 250kHz.

Data transfer was through two alternating DMA-channels that I mmap-ed
to user space. Thus, data capture needed cpu time only for creating 
time stamps and re-triggering the DMA.

The Meilhaus ME4680IS, as supported by comedi/me4000, seemed to be 
a fine replacement (up to 500kHz, "snap-shot"-mode for up to 8 
channels ...) but it has only a 1k/2k samlpes FIFO. For each interrupt 
handling, i.e. insw of 1024 samples, it takes 1.1ms. At full rate, 
this is mor than half the cpu time. Thus it is unusable for us.

The DT300x cards are claimed to be supported by comedi, but dt300.c 
of comedi-0.7.70 says "There is code to support AI commands, but it 
may not work" - ouch.

Which >12channel 12bit, >300kHz analog in, continuous scan PCI-bus
card can be used with acceptable cpu load?


Thank you in advance,
Gerhard.

Received on 2006-04-17Z19:56:08