ZyXEL Communications 3356P user manual Command Description

∙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.

∙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.

∙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

ATV1

Select numerical result code

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?

8 Basic Modem Operation