View source for DB9 to DB25 Conversion Pinout

Pinout and COM Port Summary Card
			<table border="1" cellpadding="2" cellspacing="0" width="400">
				
					<tr>
						<td align="center" valign="bottom" width="100"><font class="basic" face="arial" size="-2"><b>EIA-232-E (RS-232)<br />
						Function</b></font></td>
						<td align="center" colspan="2" valign="bottom" width="40">
						<table cellpadding="0" cellspacing="0">
							
								<tr>
									<td align="center" colspan="2" valign="top"><font class="basic" face="arial" size="-2"><b>PIN #</b></font></td>
								</tr>
								<tr>
									<td valign="top"><font align="center" class="basic" face="arial" size="-2"><b>DB-25 </b></font></td>
									<td valign="top"><font align="center" class="basic" face="arial" size="-2"><b>DB-9 </b></font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="bottom" width="100"><font class="basic" face="arial" size="-2"><b>EIA-530<br />
						Function</b></font></td>
						<td align="center" valign="bottom" width="40"><font class="basic" face="arial" size="-2"><b>PIN #<br />
						DB-25</b></font></td>
						<td align="center" valign="bottom" width="40"><font class="basic" face="arial" size="-2"><b>TO<br />
						DTE</b></font></td>
						<td align="center" valign="bottom" width="40"><font class="basic" face="arial" size="-2"><b>TO<br />
						DCE</b></font></td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">Shield</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">1</font></td>
						<td align="center" valign="top">&nbsp;</td>
						<td valign="top"><font class="basic" face="arial" size="-2">Shield</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">1</font></td>
						<td align="center" valign="top">&nbsp;</td>
						<td align="center" valign="top">&nbsp;</td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">Transmit Data (TD)</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">2</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">3</font></td>
						<td valign="top">
						<table cellpadding="0" cellspacing="0" width="100%">
							
								<tr>
									<td rowspan="2" valign="top"><font class="basic" face="arial" size="-2">Transmit Data</font></td>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(A)</font></td>
								</tr>
								<tr>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(B)</font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">2<br />
						14</font></td>
						<td align="center" valign="top">&nbsp;</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">&gt;</font></td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">Receive Data (RD)</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">3</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">2</font></td>
						<td valign="top">
						<table cellpadding="0" cellspacing="0" width="100%">
							
								<tr>
									<td rowspan="2" valign="top"><font class="basic" face="arial" size="-2">Receive Data</font></td>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(A)</font></td>
								</tr>
								<tr>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(B)</font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">3<br />
						16</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">&lt;</font></td>
						<td align="center" valign="top">&nbsp;</td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">Request To Send (RTS)</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">4</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">7</font></td>
						<td valign="top">
						<table cellpadding="0" cellspacing="0" width="100%">
							
								<tr>
									<td rowspan="2" valign="top"><font class="basic" face="arial" size="-2">Request To Send</font></td>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(A)</font></td>
								</tr>
								<tr>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(B)</font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">4<br />
						19</font></td>
						<td align="center" valign="top">&nbsp;</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">&gt;</font></td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">Clear To Send (CTS)</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">5</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">8</font></td>
						<td valign="top">
						<table cellpadding="0" cellspacing="0" width="100%">
							
								<tr>
									<td rowspan="2" valign="top"><font class="basic" face="arial" size="-2">Clear To Send</font></td>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(A)</font></td>
								</tr>
								<tr>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(B)</font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">5<br />
						13</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">&lt;</font></td>
						<td align="center" valign="top">&nbsp;</td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">DCE Ready (DSR)</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">6</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">6</font></td>
						<td valign="top">
						<table cellpadding="0" cellspacing="0" width="100%">
							
								<tr>
									<td rowspan="2" valign="top"><font class="basic" face="arial" size="-2">DCE Ready</font></td>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(A)</font></td>
								</tr>
								<tr>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(B)</font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">6<br />
						22</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">&lt;</font></td>
						<td align="center" valign="top">&nbsp;</td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">Signal Ground (SG)</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">7</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">5</font></td>
						<td valign="top">
						<table cellpadding="0" cellspacing="0" width="100%">
							
								<tr>
									<td valign="top"><font class="basic" face="arial" size="-2">Signal Ground</font></td>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(A)</font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">7</font></td>
						<td align="center" valign="top">&nbsp;</td>
						<td align="center" valign="top">&nbsp;</td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">Received Line Signal Detector (DCD)</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">8</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">1</font></td>
						<td valign="top">
						<table cellpadding="0" cellspacing="0" width="100%">
							
								<tr>
									<td rowspan="2" valign="top"><font class="basic" face="arial" size="-2">Received Line Signal Detector</font></td>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(A)</font></td>
								</tr>
								<tr>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(B)</font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">8<br />
						10</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">&lt;</font></td>
						<td align="center" valign="top">&nbsp;</td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">DTE Ready (DTR)</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">20</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">4</font></td>
						<td valign="top">
						<table cellpadding="0" cellspacing="0" width="100%">
							
								<tr>
									<td rowspan="2" valign="top"><font class="basic" face="arial" size="-2">DTE Ready</font></td>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(A)</font></td>
								</tr>
								<tr>
									<td align="right" valign="top"><font class="basic" face="arial" size="-2">(B)</font></td>
								</tr>
							
						</table>
						</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">20<br />
						23</font></td>
						<td align="center" valign="top">&nbsp;</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">&gt;</font></td>
					</tr>
					<tr>
						<td valign="top"><font class="basic" face="arial" size="-2">Ring Indicator</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">22</font></td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">9</font></td>
						<td valign="top"><font class="basic" face="arial" size="-2">N/A</font></td>
						<td align="center" valign="top">&nbsp;</td>
						<td align="center" valign="top">&nbsp;</td>
						<td align="center" valign="top"><font class="basic" face="arial" size="-2">-----</font></td>
					</tr>
				
			</table>


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