DB9 to DB25 Conversion Pinout

Pinout and COM Port Summary Card

EIA-232-E (RS-232) Function	PIN # DB-25 DB-9		EIA-530 Function	PIN # DB-25	TO DTE	TO DCE
Shield	1		Shield	1
Transmit Data (TD)	2	3	Transmit Data (A) (B)	2 14		>
Receive Data (RD)	3	2	Receive Data (A) (B)	3 16	<
Request To Send (RTS)	4	7	Request To Send (A) (B)	4 19		>
Clear To Send (CTS)	5	8	Clear To Send (A) (B)	5 13	<
DCE Ready (DSR)	6	6	DCE Ready (A) (B)	6 22	<
Signal Ground (SG)	7	5	Signal Ground (A)	7
Received Line Signal Detector (DCD)	8	1	Received Line Signal Detector (A) (B)	8 10	<
DTE Ready (DTR)	20	4	DTE Ready (A) (B)	20 23		>
Ring Indicator	22	9	N/A			-----

This table is from http://www.bb-elec.com/Learning-Center/All-White-Papers/Serial/Quick-Reference-Card-RS-232-DB9-DB25-pinouts-level.aspx

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