... with a multiple interface circuit that can handle RS-232 serial interfaces and multi-mode or single- mode fiber. ... , OUT, GND Fiber signalIN, OUT Working formatAsynchronism, point to point or multi-pointDirection controlAdopt automatic send data control , auto distinguish ... -232 port 15MOptic port transmission Multi-mode 2KM, signal-mode 20,40,60KMLoading point to pointInterface protection 600W surge ...