Is the cRIO 9012 serial port 5V logic high?

[AMP12]

I need to output a serial signal that is 5V TTL from my cRIO-9012.  I'm able to output values from COM1, but they are all different from what characters I'm expecting to see on my display device.  Through some of my searching here, I've seen mention to the possibilty that the RIO is 3.3V logic high instead of 5V. (as seen here)

Can anyone verify this for me.  I don't have an osciliscope at my disposal to do it myself.

[WearWolf]

Hello AMP12,

The COM port follows RS-232 standards and is not compatible with TTL. TTL uses levels of 0 and +5V while RS-232 uses -3 to -25 as a logic high and +3 to + 25 as a logic low.