I need to interface some old equipment that requires +-12V on its serial port. Would PCI-8430/2 do the job? How can one set the output voltage levels for this card? Can it be used just as another COM port, i.e. not NI specific?
The old serial ports voltage levels are typical +/- 12V But most IC's from that time will operate at +/- 5V. This depends on speed (probably not that fast) and length of the cable. That is for the communication part.
But if the device you are connecting retrieves it's power from the line the voltage could be too low. This can be solved but you need to know more about the device.