Hello everyone, I have got an xy motion table. There are two optical sensors (TCST2000) on each axis, and both of them are connected to an RS232 male connector.(See the picture and hand drawn below)

RS232:
I know how to connect one optical sensor to Arduino board, but I don't know how to connect four sensors to the board. Does anybody have ideas about it? Thank you very much.
Connection for one sensor and the sensor test circuit would be help.
