02-20-2020 03:51 AM
Is there a way to increase the Period in the Timing Sheet of Digital Pattern Editor over the 4E-05 maximum?
I need to run a digital test at low speed, but I do not find a good way to do it using the Digital Pattern Editor. Previously I used the Digital Waveform Editor and there was a tool, Resample Waveform, which allowed to expand a waveform. That could be a way to get around the problem. But I also do not find that possibility in the Digital Pattern Editor.
02-28-2020 06:24 AM
Hi FJR0,
There should not be any limits on how slow you can run a digital test. Have you tried looking at the Specification.specs tab and specifying a lower frequency for the period? Also under the timing tab you can specify a formula as to the frequency you want to output your data at as a function of the period. For an example of how to implement this, please navigate to Help>>Getting Started Example and have a look at the example called SPI Example.
I hope this helps.
02-28-2020 07:35 AM
Looking at the spec sheet for the PXIe-6570, it seems that this is some hardware limit. The vector period range is specified as 10 ns to 40 us, so it can not run slower than 25 kHz. What I am doing at the moment is to use a repeat(25) Opcode for each vector in the pattern to reduce the speed to 1 kHz. But it does not look like the ideal solution.
02-28-2020 10:19 AM
You are correct, for your application the characteristics of the PXIe-6570 are the limiting factor. A possible solution would be to use different hardware that has the characteristics you require.
03-05-2020 01:37 PM
An alternative is to oversample by using repeat opcode in each vector.
Example, max vector period if 40us but you want a period of 120us, better to use NR drive format, use repeat(3) on each vector. This way you can achieve the 120us slow vector.
Caution! - RL, RH, SBC don't work well will oversampling and it will still be at the specified vector period.