Dear NIDev Community,
I'm currently looking into implementing an application for digital pattern testing of a high channel count device.
The example that closely matches my application is the memory test reference design from NI web (did_mem_test.zip).
Memory Test Reference Design
In the reference design, a single HSDIO device is used to generate a write and compare pattern and the errors analyzed. In my application, I will need to distribute the digital signals across several HSDIO modules since each module has limited digital lines.
Module 1 and 2: Data lines
Module 3: Address lines
Module 4: Clock, chip enable, etc.
I would need your kind help to understand how I should implement the reference design to fit an application that spans across several modules. If you are able to give me a simple example code I will be able to move ahead from there.
My intention is to use HWS waveform patterns created using the Digital Waveform Editor and if possible to use NI-TCLK to synchronize the devices. I have attached a VI that I had modified from an example program but I'm not sure if I'm implementing it correctly. I've also zipped the reference design code too.
I'm using four PXI-6551 devices and LabVIEW 2013.
Thank you for your kind help.
You will want to using the DAQmx Timing VI to set the sample clocks of all of the cards to the same clock. Just one the first card's sample clock to make it easy. You will also want to use a trigger line to tell all of the cards to start outputting and reading the digital signals.
Thank you very much for your reply.
Would this require an external connection from the CLKOUT to CLKIN pins for all the devices connected? Or alternately the DDC_CLKOUT of the master and and Strobe pins of the slave devices to be connected physically?
Is there any possibility to use NI-TClk for this application without any external connections?
Thank you once again.
All of these triggers and clocks can be sent using the PXI backplane. So as long as all of the cards are in the same PXI chassis, no additional connections will be needed.