NI-8452 Stream Mode more than 64bits?

[DavidSands]

I hava an SPI ADC which I want to read using the stream API for high conversion rates (using the NI-8452) but want to read back all 7 ADC channels in one multi-read SPI command. The maximum number of bits that the stream API seems to support is 64 bits where I need to really read out about 232 (7 x 32 + 8 for the read command). Is there any way around this?

I use the stream mode to detect a DRDY event, but once a single channel is read the output on the ADC chip is reset (so subsequent interrupts will only be generated on new data).

Seems fairly limited otherwise.

[diabeticdaniel · Accepted solution]

David,

The payload that you are trying to stream is not a standard for SPI. We try to follow the SPI standards and give you up to 64 bits to stream at a time. If you cannot split your reads into separate 64 bit reads, you will be unable to perform this operation with the 8452. If you had some other interface, such as FPGA, you my be able to implement a custom SPI protocol on the FPGA. With the 8452, however, you do not have these options.

[DavidSands]

Thanks Daniel,

I suspected as much just wanted to be sure.

Regards

David.