USB 6008 output voltage is not enough?

[GerdW]

Hi ivy,

1. TTL is defined as a standard, you can read the details at Wikipedia. It mentions "5V", so that should give you a hint...

2. TTL is voltage based. You don't "send out TTL", you set logic levels...

[Joseph_Loo]

You need your pullup resistor on the digital output. See picture

[Joseph_Loo]

Missing picture

[Joseph_Loo]

Try again

[Joseph_Loo]

I am sorry,. The company standard browser will not function with the NI system. Basically, your diagram is missing the pullup resistor for the USB 6008 item. You need to have a pullup resistor for each output unit. That will then give you your proper voltage.

[ivy037]

you can attach as a attachment, you dont have to insert picture 🙂

Thanks a lot

[Joseph_Loo]

They change the system. The attachment does not work with IE 7 anymore for whatever reason. I tried multiple times.

[apok]

what exactly do you want to do?

what is your external hardware?

what do you want on/off?

the daq dig out is an open collector tied to a pull up internally that will supply near gnd voltage plus the emitter diode drop(on state), up to the pullup 5v(off state)...when you say 3.3v, it sounds like the load is drawing more current from the dig out...which is not good. that is why we use a driver/buffer for the daq