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

AT Commands N - Z
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 Options
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:

Related Commands and Registers:
 * B: Select Communication Standard (in modems that also specify speed via this command)
 * S37: Desired DCE Line Speed

O: On-Line Command
Command Description Template

Syntax:



Description:

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

Result Codes:

Related Commands and Registers:
 * 

P: Select Pulse Dialing Method
Syntax:

P

Description:

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

Result Codes:

Related Commands and Registers:
 * 
 * 
 * 
 * 
 * Bit 5

Q: Result Code Display Options
Syntax:

Q[0|1]

Description:

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

or
 * Q
 * 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.

Related Commands and Registers:'
 * S14: General Bit Mapped Options Status Bit 2

Sr=: Write to an S-Register
Command Description Template

Syntax:



Description:



Result Codes:

Related Commands and Registers:
 * 

Sr?: Read an S-Register
Command Description Template

Syntax:



Description:



Result Codes:

Related Commands and Registers:
 * 

T: Select Tone Dialing Method
Syntax:

T

Description:

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

Result Codes:

Related Commands and Registers:
 * 
 * 
 * 
 * 
 * Bit 5

V: Result Code Format Options
Syntax:

V[0|1]

Description:

Sets result code format to words or digits:

or
 * V
 * V0
 * digit responses (e.g. )


 * V1
 * (default) word responses (e.g. )

Result Codes:

Related Commands and Registers:
 * to turn on/off the responses.

W: Negotiation Progress Message Selection
Syntax:

W[0|1|2]

Description:

The command controls the contents and format of the  message:

or
 * W
 * W0
 * (default). When connecting, the modem reports the DTE/DCE speed in the  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  message. The data is reported only once, upon initial set up of the connection. Subsequent reports are disabled.

Result Codes:

Related Commands and Registers:'
 * for selecting the details of the reporting message.
 * Bits 2-3.

X: Call Progress Options
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.



or
 * X
 * 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:

Related Commands and Registers:
 * W: Negotiation Progress Message Selection

Y: Long Space Disconnect Options
Command Description Template

Syntax:



Description:



Result Codes:

Related Commands and Registers:
 * 

Z: Soft Reset Command
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:

Related Commands and Registers:
 * Serial Programming:Modems and AT Commands/& Commands
 * Serial Programming:Modems and AT Commands/& Commands
 * Serial Programming:Modems and AT Commands/& Commands