ZyXEL Communications Comet 3356, Руководство пользователя

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Basic Modem Operation 15
The Comet processes commands from left to right. The AT command that appears to the
right might over-write the command to the left if they are trying to accomplish tasks or
set modes that cannot coexist.
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If you see duplicated characters for each one you type, your Comet and software
both have their “echo” feature turned. The Comet command echo state is switched
off using ATE0 and on using ATE1 (default). To eliminate the double characters,
turn off the software’s command echo rather than using the ATE0 command. If you
see no characters in your terminal window when you type, the modem’s echo
setting is probably set to off. In this case, issue the ATE1 command.
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When a command is successfully issued and accepted, a modem responds with
what is called a “Result Code.” The Comet supports both “verbose” result codes
(i.e. “OK”), and “numerical” result codes (i.e. “0").
You can use the ATV command to set it one way or the other as follows:
Command Description
ATV0 Select numerical result code
ATV1 Select verbose result code
There are a few basic commands that do not require the “AT” command prefix. These
are as follows:
Command Description
A/ Repeats the last issued AT command once
<any key> Terminates the current connection attempt, if pressed
while modem is handshaking.
+++ Escape code sequence. Entered while the modem is in
Data Mode. Returns modem to Command Mode.
Modem Result Codes
When you execute or try to execute an AT command, your modem sends a result code to
let you know whether the command was executed. An OK result code means the AT
command you sent was executed. If you receive an ERROR code, it means the command
was invalid.
The Comet also provides result codes that show:
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Whether or not a Dial Tone was detected when the modem originated a call.
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If a busy signal was detected when the modem originated a call.
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The speed, protocol, and error control/data compression method used.
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If your modem has detected an incoming ring.