ZyXEL Communications Comet 3356P-LAN, User Manual

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16 Basic Modem Operation
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Multiple AT commands can be combined into one line. For example, AT&D2 and
AT&K0 can be combined into one line AT&D2&K0.
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.
The Comet supports several groups of AT commands:
AT Command Set/Type Example
Basic AT commands (compatible) ATB0
Extended AT& commands AT&D0
Extended AT\ commands AT\N3
Extended AT% commands AT%C1
Extended AT- commands AT-C0
S-Register command ATS0=1
S-Register inquiry command ATS0?