i am trying to send digital output signal using a NI9403 module and a CompactRIO 9068. I wrote a very simple application which i think it's correct and works, also based on the examples that i found using LabVIEW "help". I just placed an I/O FPGA node in the FPGA vi, changed it to "write" and connected it with some boolean controls. I was now wondering if the same result can be obtained using "invoke method" -> "set output data". I tried but i think i have not clear how it should work. In fact, when i run the vi i am not able to control the output signal in this way.
I am using:
-LabVIEW 2019 and the corresponding FPGA and Real Time modules;
-CompactRIO drivers 19.0;
Thank you for the attention!
Solved! Go to Solution.
As it is a DIO pin, you need to set it to be an output too. DIO pins startup in input mode since that is the safest thing to do. In input mode they are high impedance and not potentially short circuiting an external voltage that may or may not be connected to it.
Hello rolfk, thank you for the reply. Just to understand more clearly: from the project tree, I had already configured the NI9403 module as "output" right clicking on the module and selecting "properties", where i could set the initial line direction of a channel as output. Is this what you are referring to? Or do i have to change the I/O node into "write" also using the invoke method->set output data?
Or do i have to change the I/O node into "write"
also using the invoke method->set output data?
Just change the IOnode to "write" mode using its context menu (aka right-click menu)…
If you just use the IO node, then the line will automatically be set to be an output. This might not the case for the method node (would need to dig into documentation again to check), so you would need to use another method to set the output enable.