Contructing an RS-232 interface using USB interfaces Digital IO

[Bill Nye]

Hi,

I've got a NI USB interfaces to work with, which has plenty of digital IO available (USB 6259)

I need to communicate via RS-232 with a few instruments, which I've already done using USB to RS-232 devices.

However, I would like to do everything on a single NI USB DAQ interface. Is it possible to use a few digital lines from the USB 6259 to create an RS-232? It seems that this would be relatively straightforward, but I haven't heard of this being done.

[mfitzsimons]

Not recommended.  Voltage levels are different, no FIFO of communication, no UART that does bit sampling and error checking, no clock for data, a lot harder than you think it would be.