Serial Programming/Modems and AT Commands/Commands N - Z

Hayes-compatable Modems and AT Commands References: -- Special AT Commands and Character Sequences -- AT Commands A - M -- AT Commands N - Z -- AT& Commands

AT Commands N - ZEdit

This module explains the AT commands N to Z as used by a "generic" Hayes-compatible modem. Different modems use slightly different commands. However, this list is supposed to be as "generic" as possible, and should not be extended with modem-specific commands. Instead it is recommended to provide such command lists in an Appendix.

N: Negotiation of Handshake OptionsEdit

Syntax:

N[0|1]

Description:

Controls whether during the handshake it is acceptable to fall back to a lower connection speed than specified by the S37 register. N0 indicates that fall back is not acceptable, N1 indicates that fall back is acceptable.

Result Codes:

Result Codes
Code Description
OK Parameter was valid
ERROR Otherwise

Related Commands and Registers:

O: On-Line CommandEdit

Command Description Template

Syntax:

<The syntax of the command, when necessary in EBNF>

Description:

Return a modem to data mode when it is on line and in command mode.

Result Codes:

Result Codes
Code Description
OK Parameter was valid <description of success>
ERROR Otherwise <description of failure>

Related Commands and Registers:

  • <Link list of related commands and registers>

P: Select Pulse Dialing MethodEdit

Syntax:

P

Description:

Sets the default dialing method to pulse (rotary) dialing. The setting is valid until it is either changed by using the T command, or a T modifier with the D command.

Result Codes:

Result Codes
Code Description
OK Parameter was valid

Related Commands and Registers:

Q: Result Code Display OptionsEdit

Syntax:

Q[0|1]

Description:

The command allows to configure if result codes are supposed to be send to the DTE or not.

Q

or

Q0
(default) Result codes are send to the DTE.
Q1
No result codes are send (silent mode).

Result Codes:

Result codes are only send if the option is turned on.

Result Codes
Code Description
OK Parameter was valid
ERROR Otherwise

Related Commands and Registers:'

  • S14: General Bit Mapped Options Status Bit 2

Sr=: Write to an S-RegisterEdit

Command Description Template

Syntax:

<The syntax of the command, when necessary in EBNF>

Description:

<Description of the command, including information about the purpose and effects>

Result Codes:

Result Codes
Code Description
OK Parameter was valid <description of success>
ERROR Otherwise <description of failure>

Related Commands and Registers:

  • <Link list of related commands and registers>

Sr?: Read an S-RegisterEdit

Command Description Template

Syntax:

<The syntax of the command, when necessary in EBNF>

Description:

<Description of the command, including information about the purpose and effects>

Result Codes:

Result Codes
Code Description
OK Parameter was valid <description of success>
ERROR Otherwise <description of failure>

Related Commands and Registers:

  • <Link list of related commands and registers>

T: Select Tone Dialing MethodEdit

Syntax:

T

Description:

Sets the default dialing method to tone (DTFM) dialing. The setting is valid until it is either changed by using the P command, or a P modifier with the D command.

Result Codes:

Result Codes
Code Description
OK Parameter was valid

Related Commands and Registers:

V: Result Code Format OptionsEdit

Syntax:

V[0|1]

Description:

Sets result code format to words or digits:

V

or

V0
digit responses (e.g. 1)
V1
(default) word responses (e.g. CONNECT)


Result Codes:

Result Codes
Code Description
OK Parameter was valid
ERROR Otherwise

Related Commands and Registers:

W: Negotiation Progress Message SelectionEdit

Syntax:

W[0|1|2]

Description:

The command controls the contents and format of the CONNECT message:

W

or

W0
(default). When connecting, the modem reports the DTE/DCE speed in the CONNECT message. The speed is reported only once, upon initial set up of the connection. Subsequent reports are disabled.
W1
When connecting, the modem reports the line speed, error correction protocol, and the DTE/DCE speed. The data is reported only once, upon initial set up of the connection. Subsequent reports are disabled.
W2
When connecting, the modem reports the line speed in the CONNECT message. The data is reported only once, upon initial set up of the connection. Subsequent reports are disabled.

Result Codes:

Result Codes
Code Description
OK if parameter was valid (0, 1, 2)
ERROR Otherwise.

Related Commands and Registers:'

X: Call Progress OptionsEdit

Syntax:

X[0|1|2|3|4]

Description:

The command governs the type and verbosity of connect message responses. If the modem is in facsimile mode (+FCLASS=1), the only message sent to indicate a connection is CONNECT without a speed indication.

X

or

X0
blind dial, no busy detect, CONNECT.
X1
blind dial, no busy detect, CONNECT xxxx.
X2
dial tone detect, no busy detect, CONNECT xxxx.
X3
blind dial, busy detect, CONNECT xxxx.
X4
full monitor, all messages, CONNECT xxxx.

where xxxx = DTE rate or DCE rate.

Note that the connect message response is a function of Wn, Xn and \Vn.


Result Codes:

Result Codes
Code Description
OK Parameter was valid (0,1,2,3,4,5)
ERROR Otherwise

Related Commands and Registers:

Y: Long Space Disconnect OptionsEdit

Command Description Template

Syntax:

<The syntax of the command, when necessary in EBNF>

Description:

<Description of the command, including information about the purpose and effects>

Result Codes:

Result Codes
Code Description
OK Parameter was valid <description of success>
ERROR Otherwise <description of failure>

Related Commands and Registers:

  • <Link list of related commands and registers>

Z: Soft Reset CommandEdit

Syntax:

Z (common)
Z[0|1|2|3] (US Robotics)

Description:

Soft reset is started. If modem is connected, connection is dropped. Last saved profile is loaded from NVRAM to RAM. No more commands are read from the command line.

Result Codes:

Result Codes
Code Description
OK Soft reset succeeded.
ERROR Command failed.

Related Commands and Registers:


Hayes-compatable Modems and AT Commands References: -- Special AT Commands and Character Sequences -- AT Commands A - M -- AT Commands N - Z -- AT& Commands

Last modified on 17 January 2013, at 13:02