Basic questions regarding the NI PCI-5640R

[twitzel]

Hello forum,

I'm asking a number of very simple questions here, because the sales support has no information about this product and referred me here.

We are considering using this card to implement a basic NMR spectrometer/MRI imager, but have a number of questions whether this card can be used for our purposes. What it basically needs to do is IQ modulation and demodulation and ADC and DAC of the envelope with a bandwidth of say 2MHz. Our center frequencies will be in the range of 0.1 to 10 MHz. My questions are now:

A) Can the center frequencies be in the above range, or is there a lower limit?

B) How long (in samples) is the ADC/DAC buffer?

C) Does this card have any way to receive or transmit TTL trigger pulses?

D) Can this card be synchronized to other RF equipment (i.e. 10 MHz clk input ?)

E) What software would one have to buy in addition to the card in order to use it, and are there student versions of

    that software (this is a pure research project run by a graduate student with tight budget)?

Thanks, Thomas Witzel

[jaced]

Hi Thomas,

I believe I have fully addressed your questions below, please feel free to post back is anything is unclear.

A) Can the center frequencies be in the above range, or is there a lower limit?

The input and output channels of the 5640R are AC coupled. More detailed information about the frequency ranges/ flatness can be found in the specifications. The specified lower cut-off frequency is 50kHz which means it is the -3dB point. Flatness however is specified to -1dB from 250kHz to 80Mhz.

B) How long (in samples) is the ADC/DAC buffer?

When using LabVIEW FPGA this is user configuration. However when using the fixed personality instrument driver the DMA FIFOs are the following lengths, AI is 16kS and AO is 4kS.

C) Does this card have any way to receive or transmit TTL trigger pulses?

Yes there are 6 user configurable TTL digital I/O lines. More information can be found on page 5 of the specifications.  

D) Can this card be synchronized to other RF equipment (i.e. 10 MHz clk input ?)

When programmed in the LabVIEW FPGA environment the user has the option to use either internal, external, or external reference. More information on this can also be found on page 5 of the specifications.

E) What software would one have to buy in addition to the card in order to use it, and are there student versions of that software (this is a pure research project run by a graduate student with tight budget)?

 If you do not wish to do any programming in FPGA then you will only need LabVIEW and the NI-5640R instrument driver (which is included with the hardware). However if you wish the perform any operations on the FPGA you will need to purchase the LabVIEW FPGA module. I am not overly familiar with the pricing structure and your local sales rep would be much more capable of answering this portion of the question.  

[jaced]

Some further clarification on item B from above. When using LabVIEW FPGA, buffer sizes are configurable. The PCI bus has enough bandwidth to continuously stream samples to or from the device at the full rate of 25MS/s for a single channel indefinitely (assuming your processing of the samples on the host can keep up). If you need to use more than a single channel (there are 2 input and 2 output channels), then there will be bandwidth limitations that may will be partly dependent on your system performance. When using the fixed personality instrument driver, both the host side and device side buffers have been sized to support continuous streaming without overflowing (without loosing any samples) at the full rate of a single channel. The actual buffer sizes vary in different scenarios, but on a 32bit machine, you can acquire at least 1 MSamples which will be buffered in host memory before you fetch them for processing.