How To set initial value on DIO channel for LED (cRIO 9068, NI-9403 DIO)

[jwscs]

hi everyone!

so our electrician added LEDs to our device, and i want them to signify things.

my problem is, that the led after starting the cRIO is OFF, but (i presume) after the labview runtime on the cRIO starts, it becomes ON.

this is not what i want, i want to turn the LED on at a specific step in my program.

i am unsure how to set the initial state so that it remains OFF.

any pointers are welcome.

if more info is needed, please ask.

what i have tested so far:

end a test program with the desired state of the led, but after reboot it eventually turns on again by itself.

set channel value to TRUE in DSM (which means LED is OFF), but same result as above.

[nanocyte]

Usually, all the DIO is tristated when the RIO is powered on. There's no state change when the runtime starts unless you program it to do so. Given that, I'm assuming your led has inverted logic (you could send us a schematic for us to verify). If that's true, the best you can do is setting your FPGA to load at power up which will take a second or so.

https://knowledge.ni.com/KnowledgeArticleDetails?id=kA00Z000000P9mASAS

Also, it might be useful to post your test code so we can make sure you're not accidentally setting some states unintentionally.

[jwscs]

hi and thank you for your answer.

my colleague said that the led does not have inverted logic.

and unfortunately we don't have the FPGA subscription, we can only use the scan interface.

anyways .... we solved the problem by using a small  npn-transistor as switch.

regards