How to set a digital output device to power up on TTL low level

[bmihura]

I have an NI USB-6501, and I want it to power up with its TTL outputs low (0 volts) or high-Z, not high (5 volts). Powering up high will ruin my equiment. How do I make that happen?

[johnsold]

According to the User Guide the power up state is high impedance input with 4700 ohms pull up to +5 V.  This device does not appear to have any other options.

You either need to get a different DAQ devices or add external circuitry which will not connect the 6501 to your equipment until it has been driven through a specified High, Low, High, Low sequence which you define and control through another DO line.

Lynn