ZyXEL Communications omni series user manual Serial Port Interface, Pin, Dce

19 Serial Port Interface

EIA-232D 25 Pin Serial Port Interface

Pin	ITU-TSS	EIA	Signal/Pin	Signal
Number	Signal	Signal	Description	Direction
	Name	Name		DTE -DCE
1	101	AA	Protective Ground	⇔
			(GND).
2	103	BA	Transmitted	⇒
			Data(TXD).
3	104	BB	Received	⇐
			Data(RXD).
4	105	CA	Request To Send	⇒
			(RTS).
5	106	CB	Clear To Send	⇐
			(CTS).
6	107	CC	Data Set Ready	⇐
			(DSR).
7	102	AB	Signal Ground	⇔
			(GND).
8	109	CF	Data Carrier	⇐
			Detected (DCD).
15	114	DB	Transmit Clock	⇐
			Signal (source:
			DCE).
17	115	DD	Synchronous Receive	⇐
			Clock.
18	141		Local Analog	⇒
			Loopback Test.
20	108/2	CD	Data Terminal Ready	⇒
	108/1		(DTR).
			Connect DCE to line.
21	140		Remote Digital Loop	⇒

152 Serial Port Interface