DMA and Labview

[Robert R]

Hi

I'm using the pci6035 card and must synchronize write and read data.
I set AI and AO for operate with DMA (Set Daq Device information for
each of this) and with Route Signal set to AO Update (AI Read and AO
Single update in loop)
(In card specification I've found how to do it :
Invoke AI Clock Config VI with clock source code set to PFI pin, high to
low, and clock source string set
to 5.Invoke Route Signal VI with signal name set to PFI5 and signal
source set to AO Update).
I did this,but still become an error :No DMA channel is available for us
(10455).
What;s wrong ?

Thanks
Robert

[Erin_B.]

The PCI-6035E only has one available DMA channel. Therefore, one of your I/O operations must use interrupts. Interrupt-driven transfers are slower than DMA transfers, but using DMA for AI and interrupts for AO will not affect their synchronization. They can still acquire data and update the DAC using the same clock signal. That signal may just have to be slower if the AO can't keep up with the clock rate.

Also, you set the transfer mode to interrupts using Set DAQ Device Info VI. If you find that you need rates only achievable by DMA transfers, our standard E-Series line of data acquisition boards have 3 on-board DMA channels. It is just the low-cost E-Series boards like the 602xE, 6034E, and 6035E that only have 1 onboard DMA channel.

Regards,
Erin