Some basic questions on the NI-Digital Pattern Instrument PXIe-6570

[Chris_NI]

Hi NI Team,

I've recently purchased the NI 6570 PXI module and I'm learning to use it now. The goal is to use the module to measure a device with an SPI interface. I've been reviewing some pages and example programs along with the Digital Pattern Editor (ultimately I'm going to be using python for working with the 6570 and so I'm using the NIDigital python module).

It seems that if you want to burst any sort of pattern you're going to have to create it in the .digipat format. Is that a true statement? Is there a way to command the 6750 to send patterns without first creating the .digipat file? I ask this because:

1. It would be nice not to be limited by IO in any capacity
2. For my application, I might want to alter the pattern I'm sending out based on what the 6570 has read. The flow as I understand it now seems to be that this dynamic pattern loading isn't possible and I have to think and create every possible pattern beforehand or create these .digipat files on the fly. I don't really wish to operate this way unless necessary. 

I was hoping to use this template from the Digital Pattern Editor:

Where perhaps the "D" in vectors 5&6 are something I can dynamically alter. Is that the case? If not, may I request a little more information on what is going on in that point of sending commands?

Thank you for your time,

Chris

[santo_13]

1. Yes, patterns have to be pre-defined in digipatsrc format (optional), compile into digipat and loaded into the instrument to burst
2. Please explain what you mean by limited by IO in any capacity
3. Source and capture patterns exist for the sole reason for bringing in dynamic data content of the pattern, in the case of SPI protocol, the dynamic content will be register address, register data
4. Yes pin state "D" along with "source" opcode helps you replace the D by a digital state that you determine prior to the execution of the pattern, this could be the register address and data that are part of the SPI write/read

Since you're new to using the 657x instrument, I would recommend taking up this training - https://learn.ni.com/learning-paths/device-testing-with-digital-pattern-instruments

It will save you several weeks of learning curve and the majority of your current questions will be answered.

[Chris_NI]

Hi Santhosh, 

Thank you for your message! It helps a lot. For the IO part, I was considering read and write operations on the hard drive. I was thinking the flow would have to be:

1. Generating and writing the ASCII .digipat file to disk.
2. Then converting to binary to upload to the instrument.
3. Followed by a reading of the disk to upload to the instrument.

And would be done dozens of times depending on dynamic data. And so the write and read operations of the disk will eventually be the bottleneck of testing as it would be slower than actually bursting the pattern. Of course, as you explained, this isn't the way to work with the instrument.

Thank you for the link, I will try to see if I have access to this training.