How to read a pin when you generate the output

[Hector D]

Hi Im working with the C Rio 9004 and the module crio 9411 and crio 9474. I am outputing a PWM signal in the pin DO0 of the 9474 in order to trigger an ultrasonic sensor. The sensor sends a TTL signal as a response in pin DI7 of 9411and I need to make a signal processing, by this I mean that I need to NOT the DO0 and then AND it with the DI7. Well the problem is that I don't know how do i read the output signal im generating in order to make the NOT/AND convertion with the imput signal. The PWM is being generated in the FPGA and the signal process in the Host. 

Thanks in advance,

Hector.  

[Brinoceros]

Hi Hector,

A few thoughts I have..   As for "reading the output," this does not make a lot of sense. Since  you are generating the output, you can take the same generated signal that is passed to the output and use that internally since you know it is the same as the output.  Otherwise, I suppose you could loop the output back to an input, but this doesn't seem necessary.

 For the NOT/AND operations, you could either do this on the host or the FPGA.  On the FPGA you could just directly operate on the generated output and read input, then send the results back to the host.  To do this on the host you would need to pass both back to the host and do the operations there.

Just a few thoughts.  Hope this helps!