Digital Output signals - all High state - How to change Low?

[Grey]

Hi,

I'm using NI USB 6501using that i'm controlling the relays.

After wiring my hardware, once i power up all relays are by default in ON condition.

I want the DO signals of NI USB 6501should Low by default.

But my case is all DO signals are HIGH state.

I opened MAX and check the test panels there i saw it configured HIGH state.

How to change Digital Output lines as LOW ?

if you need more information to understand my questing feel free to reply me

thanks.

[crelf]

Sorry to tell you this, but the 6501 doesn't have definable start up states. You could use an inverter, rewire your relays to operate oppositely, or replace the 6501 with an M-Series WSB DAQ device that does support definable start up states.

[Grey]

Oh.. Thanks very much for your information.

I didn't know this before.

[Grey]

I'm thinking to use IC 7404. Can it work as inverter for NI USB 6501?

[Tim_S]

I've gotten around this issue (before there was programmable power on state) by using one of the outputs to turn on a time-delay relay. The relay became part of the control power circuit.