Lantronix MSS1-T, Reference Manual

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Troubleshooting Modem Configuration Checklist
B - 5
B.4.6 SHOW SERVER
Use this command before and/or after issuing other commands to view the current MSS setup.
B.4.7 FLUSH NVR
This command is used to restore the MSS’s non-volatile RAM to its factory default settings. It will
reset everything that is configurable on the server, including the unit’s IP address.
B.4.8 FLASH
This command will force the MSS to download new operational code and reload it into Flash
ROM. This is necessary when a new version of software is released and you wish to upgrade your
unit. If the server cannot download the file, the code in Flash ROM will still be usable.
See Appendix E in the CD-ROM copy of the documentation for more information on updating
software.
B.5 Modem Configuration Checklist
NOTE: Modem functions do not apply to the MSS485.
Most modem problems are caused by cabling mistakes or incorrect modem configuration. How-
ever, the following items should be verified after any modem configuration, and re-checked when
there is modem trouble.
• The modem must disconnect immediately when DTR is de-asserted.
• The modem must assert CD (or DSR, if connected) when connected to another modem.
It must not assert CD when disconnected. The modem may optionally assert CD
during outbound dialing.
• The modem and MSS must agree on the flow control method and baud rate scheme.
• The modem must not send result codes or messages to the server except optionally
during outgoing calls.
• The modem should be set to restore its configuration from non-volatile memory when
DTR is dropped.
• The modem should be configured to answer the phone if incoming connections are to
be supported. Generally this is done with the ats0=1 command.
• The modem should not be configured to answer the phone unless the MSS asserts DTR.
• MSS Modem control must be enabled. Using modems on ports without modem control
enabled will lead to security problems.
The MSS Autobaud feature should be enabled only when required.