Lantronix ETS Reference Manual - page 287
Troubleshooting
Modem Configuration Checklist
B-3
Most modem problems are caused by cabling mistakes or incorrect modem configuration. However, the
following items should be verified after any modem configuration, and re-checked when there is modem
trouble.
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Set the modem to disconnect immediately when DTR is de-asserted.
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Set the modem to 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.
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Set the modem and ETS for the same flow control method and baud rate scheme.
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Set the modem to not send result codes or messages to the server, except optionally during outgoing
calls.
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Set the modem to restore its configuration from non-volatile memory when DTR is dropped.
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Set the modem to answer the phone if incoming connections are to be supported. Generally this is
done with the ats0=1 command.
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Set the modem so that it does not answer the phone unless the ETS asserts DTR.
◆
Enable Modem control on the ETS. Using modems on ports without modem control enabled will lead
to security problems.
◆
Disable the ETS Autobaud feature unless it is strictly required by your modem/application.