Is it necessary to connect an external voltage source in order to produce a digital output signal?

[Valvemed]

Hello,

I'm using a 6232 PCI card and from what i understand from the manual i have to connect an external power supply to the VCC port in order to generate a binary signal. I would like to ask:

1. is that correct? (I would like to be sure before any misunderstandings lead me to burning my NI card)

2. since I'm using a floating voltage DC supply, and the D.O ground is a reference ground and not true ground. is it enough to connect just the " + " side of the DC supply to the VCC port or is it necessary to short-circuit the D.O ground (on the NI card) and the " - " of the DC supply?

Thank you.

[Starla_T.]

Hi Valvemed,

When you connect an external voltage source, the correct connection will depend on whether you are sinking or sourcing.  Follow the circuit diagrams on page 6-2 and 6-3 of the manual.   Also, make sure you do not exceed the current or voltage specs of the card.   As long as you follow the diagrams in the manual and don't exceed the specifications, the card should be safe.

Hope this helps, Best Regards,

Starla T.