fpga interface to daq

[Andrew_Quick]

I have a repetitive loop in a PXI-7813R producing patterns. The output of the PXI-7813R is TTL but I need 0 to 15V levels. I have in the same PXI rack a DAQ device (PXI-6528) which can handle the voltage levels. The question is, can I somehow link the patterns from the 7813R to the 6528 using the PXI backplane and leave this running while I carry on using the PXI rack for other functions?

Thanks

Andy Quick

[Alex-D]

Take a look at this KB: http://digital.ni.com/public.nsf/allkb/A639B5A8EFFF1717862578A9006F643E?OpenDocument The VI's shown in it are the same that you would want to use to transfer the data. Instead of the constants set it up to output your data. Then on the other module read from that trigger line. Using those should allow you to transfer the data across the backplane by using the trigger lines.  

[Andrew_Quick]

HI,

Thank you. So this shows that I can drive a PXI trig line high and low from the FPGA. What I do not know is if I can program the output of the PXI-6528 to follow the logic level of the trig line. Looking at the routing table in MAX for the 6528 it shows;

Which implies that there is a way to have port3/line1 follow the logic status of PXI_Trig1. PLease can you give me an example of the VIs needed to make the 6528 do this as I cannot work it out.

Thanks

Andy

[crossrulz · Accepted solution]

The problem with the PXI-6528 is that it is software timed.  Which means trigger lines won't help you here.

What you need to do is do some hardware work.  You can have the PXI-7813R output the patterns and drive an opto-coupler or FET circuit to change the voltage level to 15V.  Or maybe there is a digital buffer out there that can output 15V for you.

[Andrew_Quick]

That is what I thought. I don't understand what the routing table that MAX shows for the 6528 is actually telling me. It shows a link between PXI Trig lines and 6528 output channels but I do not know what that link is supposed to do. As you say, I am just going to have to put some external level shifting hardware into my solution.

Thank you.