How to generate an RS-170 signal in PXI?

[Steven P]

Could someone please indicate how I can generate an RS-170 signal with PXI instrumentation?  Is a NI 5431 capable of doing this?  I actually need to connect the RS-170 signal to eight products under test.  Can I use some type of splitter to do this?

Thanks for any help.

[kirsch]

Hello Steven.
Here's my understanding on your problem -

RS-170 is just the older black and white version of NTSC. The 5431 can generate these signals easily, as it can do full-collor NTSC.

You need to create the waveform data though. For this you could use the NI Video Toolkit, which shipped with your 5431. I don't know it the toolkit can create RS-170 signals (which are lower bandwidth and thus you can fit more of them into your generator's memory) or just the higher bandwidth but backwards compatible NTSC signals.

If it can only do NTSC signals, then you can use those directly or downsample them in order to be more efficient using LabVIEW's built-in functions.

Now, for the splitter question: I doubt the NI 5431 can provide enough current for eight DUTs in parallel. And even if it could, or if you were only testing 2 devices at the same time, I'm not sure if there would be reflections on the line that would impact your test signal. If you want to try it, set your output impedance to (I assume this is what you are using) 75 Ohms and your load impedance to 75 Ohms / No. of DUTs (each one 75 Ohms, all in parallel). However, being this video signals, you should be able to find video splitters at your local electronics store very cheaply.

I know I'm not providing complete and final answers, but hope it points you to the right direction.

Marcos