TTL serial into the cRIO RS-232 Port?

We’d like to connect a sensor to the RS-232 port of the cRIO. The sensor puts out 9600 baud, 8 bits, no parity, 1 stop bit. No flow control. Alas it’s TTL level serial so it swings between 0 and 4.5 v rather than RS-232’s spec of ±12v.

Has anyone tried this on a cRIO? I know many RS-232 devices are fine with TTL levels like this but some really want that ±12v. In what camp does the cRIO fall?

If the cRIO is a stickler, does anyone know of a RS-232 level shifter board with it’s own onboard power supply that will take in a TTL level serial signal and +5 and/or +12 and convert it into official RS232?

I do not know if it will accept TTL signals, but i know that this will work to convert the signals

Thanks. I’ve already ordered the slightly updated version of that board just in case. I’m just hoping someone has tried just running TTL level serial into a cRIO and will tell me it works fine without it.

We’re getting weird data with our first pass code in Java so we don’t know if that’s the code or an interface problem.

We have used the TTL board from the 2005, 2006 CMU Camera just fine into the RS-232 for testing to convert a microprocessor TTL into RS-232 into the CRIO-I serial port. If you have one of those laying around to try it, it works.

It will not just work - you need a converter. Several have been mentioned in this thread. Here is another choice


Good idea on the old TTL board from the CMU Cam. That would be good for testing at least (I don’t know that’s it’s an off the shelf item.) I’ll see if I can find that again.

If you didn’t modify it previously, it would be legal per [R24]. The IFI site confilicts itself (It says it’s In Stock and Discontinued right next to each other).