The NI-9870 module can be used to add RS-232 serial ports to CompactRIO systems. The serial ports can be accessed directly from the FPGA, providing flexibility in communicating with serial devices. The module has individual buffers on each port, saving space on the FPGA and allowing for easier programming.NI-9870 supports default settings for start bit, stop bit and handshaking. It uses an external power source for maximum compatibility and reliability.