DOCUMENT:Q108296 08-AUG-2001 [winnt] TITLE :9-to-25 Pin RAS Null Modem Cabling PRODUCT :Microsoft Windows NT PROD/VER:3.1 4.0 OPER/SYS: KEYWORDS:kbnetwork ====================================================================== ------------------------------------------------------------------------------- The information in this article applies to: - Microsoft Windows NT Server version 3.1 - Microsoft Windows NT Workstation version 3.1 - Microsoft Windows NT Advanced Server, version 3.1 - Microsoft Windows NT Server version 4.0 - Microsoft Windows NT Workstation version 4.0 ------------------------------------------------------------------------------- SUMMARY ======= The Windows NT Remote Access Help file includes tables showing the correct wiring of a null modem cable for use with RAS. The two tables included show the correct wiring for a 9-pin null modem cable and a 25-pin null modem cable. The following table contains the proper null modem wiring that must be used when the cable connects a 9-pin serial port to a 25-pin serial port. 25-pin Connector to 9-pin Connector ---------------------------------------------------- 2 (transmit data) <-> 2 (receive data) 3 (receive data) <-> 3 (transmit data) 4 (request to send) <-> 8 (clear to send) 5 (clear to send) <-> 7 (request to send) 6,8 (data send ready, carrier detect) <-> 4 (data terminal ready) 7 (ground) <-> 5 (ground) 20 (data terminal ready) <-> 6,1 (data send ready, carrier detect) Additional query words: prodnt nul ====================================================================== Keywords : kbnetwork Technology : kbWinNTsearch kbWinNTWsearch kbWinNTW400 kbWinNTW400search kbWinNT400search kbWinNTW310 kbWinNTSsearch kbWinNTS400search kbWinNTS400 kbWinNTS310 kbWinNTAdvSerSearch kbWinNTAdvServ310 kbWinNTS310search kbWinNT310Search kbWinNTW310Search Version : 3.1 4.0 ============================================================================= THE INFORMATION PROVIDED IN THE MICROSOFT KNOWLEDGE BASE IS PROVIDED "AS IS" WITHOUT WARRANTY OF ANY KIND. MICROSOFT DISCLAIMS ALL WARRANTIES, EITHER EXPRESS OR IMPLIED, INCLUDING THE WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL MICROSOFT CORPORATION OR ITS SUPPLIERS BE LIABLE FOR ANY DAMAGES WHATSOEVER INCLUDING DIRECT, INDIRECT, INCIDENTAL, CONSEQUENTIAL, LOSS OF BUSINESS PROFITS OR SPECIAL DAMAGES, EVEN IF MICROSOFT CORPORATION OR ITS SUPPLIERS HAVE BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF LIABILITY FOR CONSEQUENTIAL OR INCIDENTAL DAMAGES SO THE FOREGOING LIMITATION MAY NOT APPLY. Copyright Microsoft Corporation 2001.