IBM H SERIES RS/6000 User Manual

Also see for H SERIES RS/6000: Installation and service guide Installation and service guide

Xon/Xoff ModemsSome modems of the mid-80's vintage assume software flow control (Xon/Xoff)between the computer and the modem. Modems with this design send extra charac-ters during and after the transmitted data. The Service Processor cannot toleratethese extra characters. If your configuration includes such a modem, your functionalresults may be unpredictable.The sample modem configuration files included in this package do not support thesemodems, so custom configuration files would be necessary. Anchor Automation2400E is an example of such a modem.Most newer modems do not use this design. It is recommended you use modems ofnewer vintage if you experience unexplainable performance problems that may bedue to Xon/Xoff characters.Ring DetectionMost modems produce an interrupt request each time they detect a ring signal.Some modems generate an interrupt only on the first ring signal they receive. AT&TDataPort 2001 is an example of such a modem.The Service Processor uses the ring interrupt request to count the number of ringswhen Ring Indicate Power-On (RIPO) is enabled. If your modem produces an inter-rupt on only the first ring, set Ring Indicate Power-On to start on the first ring. Other-wise, you may choose to start Ring Indicate Power-On on any ring count that makesyour operation convenient.Terminal EmulatorsThe Service Processor is compatible with simple ASCII terminals, and therefore com-patible with most emulators. It is for the cases when a remote session is handed offfrom the Service Processor to the operating system that agreeing terminal emulatorsbecomes important.Switch Position Function11 *Up AT Responses Enabled (Extended Responses Disabled)12 *Down Asynchronous Operation13 UP 28.8KB Line Speed14 Up15 Up CD and DSR Normal Functions16 Up 2-Wire Leased Line Enabled* Only switches 11 and 12 are changed from the factory default settings.Appendix C. Modem Configurations C-5