V24 control and V25ter

Introduction

These commands, unless specifically stated, do not implement set syntax using "=", read ("?"), or test ("=?"). If such commands are used, the "+CME ERROR: unknown" or "+CME ERROR: 100" error result code is provided (depending on the +CMEE AT command setting).

Circuit 109 behavior &C

&C

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

Profile

No

-

+CME Error

Description

Controls how the state of RS232 circuit 109 - Data Carrier Detect (DCD) - relates to the detection of received line signal from the remote end.

Syntax

TypeSyntaxResponseExample

Action

AT&C[<value>]

OK

Defined values

ParameterTypeDescription

<value>

Number

Indicates the behavior of circuit 109

  • 0: DCE always presents ON condition on circuit 109

  • 1 (default value and factory-programmed value): circuit 109 changes in accordance with the Carrier detect status; ON if the Carrier is detected, OFF otherwise

Notes

  • See the corresponding module system integration manual for the DCD behavior during the initialization phase of the module.

Circuit 108/2 and escape sequence behavior &D

&D

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

Profile

No

-

+CME Error

Description

Controls how the state of RS232 circuit 108/2 - Data Terminal Ready (DTR) - relates to changes from ON-to-OFF transition during on-line data state.

It also controls how the escape sequence may change the on-line data state.

Syntax

TypeSyntaxResponseExample

Action

AT&D[<value>]

OK

Defined values

ParameterTypeDescription

<value>

Number

Allowed values:

  • 0: the DCE ignores circuit 108/2

  • 1: upon an ON-to-OFF transition of circuit 108/2, the DCE enters online command state and issues the final result code

  • 2: upon an ON-to-OFF transition of circuit 108/2, the DCE performs an orderly cleardown of the call. The automatic answer is disabled while circuit 108/2 remains OFF

The default and factory-programmed value is:

  • 2

+++ behavior

  • A special meaning of the &D value is provided for the +++ sequence during a PS data transfer with PPP L2 protocol (this is outside the ITU-T V.25ter recommendation [38] scope). Upon +++ sequence the PS data transfer is escaped and the system returns in the on-line command state.

  • The ATO command is used to resume the PS data transfer session.

  • If the module has a DUN/PPP activated and is in OLCM, the ATH command deactivates the PPP and the associated PDP context (if possible).

For more details, see the ITU-T recommendation V250 [39], ITU-T V.25ter recommendation [38] and ITU-T V.32 recommendation [40].

See the corresponding module system integration manual for the DTR behavior during the initialization phase of the module.

DTR, +++ behavior

Table 8. PS data mode
PS data mode (PPP L2 protocol case)

Event

DTE sends +++

DTR ON-to-OFF transition

&D0

DCE enters online command mode

No action

&D1

DCE enters online command mode

DCE enters online command mode

&D2

DCE enters online command mode

Context deactivation

Table 9. Direct Link mode
Direct Link mode

Event

DTE sends escape sequence (e.g. +++)

DTR ON-to-OFF transition

&D0

DCE enters command mode

No action

&D1

DCE enters command mode

DCE enters command mode

&D2

DCE enters command mode

DCE enters command mode

Notes

  • The escape sequence for the PS data mode with a L2 protocol different from the PPP is not ~+++, and it could be not supported.

  • S2 command is not supported and the escape sequence is fixed to "+++"

  • On the AUX UART interface, the DTR line is always considered to ON state (even if the AUX UART interface does not support the DTR line).

  • Setting a 5-wire UART configuration (for mode details, see the +USIO AT command), on the UART interface the DTR line is always considered to ON state (even if the UART interface does not support the DTR line).

Flow control &K

&K

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

NVM

No

-

+CME Error

Description

Controls the flow control mechanism. The following settings are allowed:

  • No flow control

  • HW flow control also referred with RTS / CTS flow control

  • SW flow control also referred with XON / XOFF flow control

Syntax

TypeSyntaxResponseExample

Action

AT&K[<value>]

OK

Defined values

ParameterTypeDescription

<value>

Number

  • 0: disable DTE flow control

  • 3 (default and factory-programmed value): enable the RTS/CTS DTE flow control

  • 4: enable the XON/XOFF DTE flow control

  • 5: enable the XON/XOFF DTE flow control

  • 6: enable the XON/XOFF DTE flow control

Allowed values:

  • 0, 3 (default and factory-programmed value)

Notes

  • The command handling is the same for <value> parameter 4, 5 or 6.

  • The command is accepted and stored to NVM, but has no effect if issued on CDC-ACM.

DTE-DCE character framing +ICF

+ICF

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

partial

Yes

NVM

No

-

+CME Error

Description

Sets the local serial port start-stop (asynchronous) character framing which is used in information interchange between DCE and DTE. Value 0 corresponds to the auto-detect case (if autobauding is supported).

The following restrictions must be reminded:

  • If a data frame format refers to a frame without parity (ex. <format>=3), the command is accepted, but the parity value is ignored; it is returned by the +ICF read command (and displayed in the current personal profile configuration where supported) but it has no meaning

  • The command setting is ignored when the AT command interface runs on the USB or on the SPI interface

Syntax

TypeSyntaxResponseExample

Set

AT+ICF=[<format>[,<parity>]]

OK

AT+ICF=3,1

OK

Read

AT+ICF?

+ICF: <format>,<parity>

OK

+ICF: 3,1

OK

Test

AT+ICF=?

+ICF: (list of supported <format>s),(list of supported <parity>s)

OK

+ICF: (0-3,5),(0-1)

OK

Defined values

ParameterTypeDescription

<format>

Number

  • 0: auto detect

  • 1: 8 data 2 stop

  • 2: 8 data 1 parity 1 stop

  • 3: 8 data 1 stop

  • 4: 7 data 2 stops

  • 5: 7 bit, 1 parity, 1 stop

  • 6: 7 bit, 1 stop

Allowed values:

  • 1, 2, 3 (default and factory-programmed value), 4, 5, 6

<parity>

Number

  • 0: odd

  • 1: even

Allowed values:

  • 0 (default and factory-programmed value), 1

Notes

  • Running the command on a CDC-ACM or MUX Virtual Channel interface will produce a successful result and the settings will be saved, however they will have no effect.

  • The command setting is not displayed in the AT&V information text response.

DTE-DCE local flow control +IFC

+IFC

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

NVM

No

-

+CME Error

Description

Controls the operation of the local flow control between DTE and DCE used when the data are sent or received.

When the software flow control (XON/XOFF) is used, the DC1 (XON, 0x11) and DC3 (XOFF, 0x13) characters are reserved and therefore filtered (e.g. in SMS text mode these two characters can not be input).

Since the DTE-DCE communication relies on the correct reception of DC1/DC3 characters, the UART power saving should be disabled on the module when SW flow control is used. If the UART power saving is active, the DC1/DC3 characters could be used to wake up the module’s UART, and therefore lost. In case a DC3 character (XOFF) is correctly received by module’s UART and some data is waiting to be transmitted, the module is forced to stay awake until a subsequent DC1 character (XON) is received.

The software flow control (XON/XOFF) setting is not allowed on the USB interfaces, on the SPI interface and on a multiplexer channel. See the Multiple AT command interfaces for all the behavior differences in respect to the supported interfaces.

Syntax

TypeSyntaxResponseExample

Set

AT+IFC=[<DCE_by_DTE>[,<DTE_by_DCE>]]

OK

AT+IFC=2,2

OK

Read

AT+IFC?

+IFC: <DCE_by_DTE>,<DTE_by_DCE>

OK

+IFC: 2,2

OK

Test

AT+IFC=?

+IFC: (list of supported <DCE_by_DTE>),(list of supported <DTE_by_DCE>s)

OK

+IFC: (0-2),(0-2)

OK

Defined values

ParameterTypeDescription

<DCE_by_DTE>

Number

  • 0: none

  • 1: DC1/DC3 on circuit 103 (XON/XOFF)

  • 2 (default and factory-programmed value): circuit 105 (RTS)

Allowed values:

  • 0, 2 (default and factory-programmed value)

<DTE_by_DCE>

Number

  • 0: none

  • 1: DC1/DC3 on circuit 104 (XON/XOFF)

  • 2 (default and factory-programmed value): circuit 106 (CTS)

Allowed values:

  • 0, 2 (default and factory-programmed value)

Notes

  • <DCE_by_DTE> and <DTE_by_DCE> parameters must be provided with the same value in pairs (only (0,0), (1,1) and (2,2) are allowed. The other combinations are not allowed and the "+CME ERROR: operation not allowed" error result code is returned).

  • The command is accepted and stored to NVM, but has no effect if issued on CDC-ACM.

  • The SW flow control is not supported (<DCE_by_DTE> and <DTE_by_DCE> cannot be set to 1).

UART data rate configuration +IPR

+IPR

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

partial

No

NVM

No

-

+CME Error

Description

Specifies the data rate at which the DCE accepts commands on the UART interface. The full range of data rates depends on HW or other criteria.

Syntax

TypeSyntaxResponseExample

Set

AT+IPR=[<rate>]

OK

AT+IPR=9600

OK

Read

AT+IPR?

+IPR: <rate>

OK

+IPR: 9600

OK

Test

AT+IPR=?

+IPR: (list of supported autodetectable <rate> values)[,(list of fixed only <rate> values)]

OK

+IPR: (0,2400,4800,9600,19200,38400,57600,115200),()

OK

Defined values

ParameterTypeDescription

<rate>

Number

Allowed baud rates expressed in b/s (0, if present, means autobauding):

  • 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200 (default and factory-programmed value), 230400, 460800, 921600, 3000000

Notes

  • On the UART AT interface, after the reception of the "OK" result code for the +IPR command, the DTE shall wait for at least 100 ms before issuing a new AT command; this is to guarantee a proper baud rate reconfiguration.

  • Running the command on a CDC-ACM or MUX Virtual Channel interface will produce a successful result code and the settings will be saved, however they will have no effect.

  • The command setting is not displayed in the AT&V information text response.

  • For a volatile version of this command, see +IPRX.

Volatile UART data rate configuration +IPRX

+IPRX

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

partial

No

No

No

-

+CME Error

Description

This command is a volatile variant of the +IPR AT command, conceived for the modules in which the change of the baudrate via +IPR is immediately stored in the NVM. For syntax, parameters and values refer to +IPR.

Notes

  • The command is available only on MAIN and AUX UART interfaces.

  • The command is not supported on LEXI-R10801D-00B-00.

Return to on-line data state O

O

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

Yes

No

No

-

+CME Error

Description

Causes the DCE to return to online data state and issue a CONNECT intermediate result code on DTE.

ATO command is used to resume both circuit-switched and packet-switched data call. The resume is only possible if the PPP L2 protocol is used.

Syntax

TypeSyntaxResponseExample

Action

ATO

<response>

ATO

CONNECT

Defined values

ParameterTypeDescription

<response>

String

  • CONNECT

  • NO CARRIER: the online data state cannot be resumed

Notes

  • The command provides an error result code ("+CME ERROR: operation not allowed" if +CMEE is set to 2) in the following cases:

    • The DCE is not in online command state

    • It is issued on a DCE different from the one in online command state

  • In case of PSD call, any data from the network (downlink data) received by the DCE during the on-line command state is discarded. This means that after the O command and on-line data state resume, any possible data loss has to be recovered by upper layer protocols (e.g. TCP).

Command echo E

E

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

Profile

No

-

+CME Error

Description

Controls whether or not the MT echoes characters received from the DTE during command state.

Syntax

TypeSyntaxResponseExample

Set

ATE[<value>]

OK

ATE1

OK

Defined values

ParameterTypeDescription

<value>

Number

  • 0: echo off

  • 1 (default and the factory-programmed value): echo on

Result code suppression Q

Q

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

Profile

No

-

+CME Error

Description

Determines if DCE transmits result codes to the DTE or not. When result codes are being suppressed, no portion of any intermediate, final or URC is transmitted. Information text transmitted in response to commands is not affected by this setting.

Syntax

TypeSyntaxResponseExample

Set

ATQ[<value>]

OK

ATQ1

OK

Defined values

ParameterTypeDescription

<value>

Number

  • 0 (default and the factory-programmed value): DCE transmits result codes

  • 1: Result codes are suppressed and not transmitted

DCE response format V

V

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

Profile

No

-

+CME Error

Description

Control the contents of the header and trailer transmitted with result codes and information text responses. It also determines whether the result code is transmitted in a numeric form or an alphabetic (or verbose) form. The information text response is not affected by this setting. See Information text responses and result codes for description of the result code formats.

Syntax

TypeSyntaxResponseExample

Set

ATV[<value>]

OK

ATV1

OK

Defined values

ParameterTypeDescription

<value>

Number

  • 0: DCE transmits limited headers, trailers and numeric text

  • 1 (default and the factory-programmed value): DCE transmits full headers, trailers and verbose response text

Notes

The information text response are affected by this setting.

Set to factory defined configuration &F

&F

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

No

No

-

+CME Error

Description

Resets the current profile to factory-programmed setting. Other NVM settings, not included in the profiles, are not affected.

In case of success, the response is issued using the configuration of the result codes format (Q, V AT commands) loaded from the factory-programmed profile. The other DCE settings are applied after the response has been sent.

For more details on the settings stored in the profiles, see the Parameters stored in profiles.

Syntax

TypeSyntaxResponseExample

Action

AT&F[<value>]

OK

Defined values

ParameterTypeDescription

<value>

Number

Only 0 allowed

Store current configuration &W

&W

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

No

No

-

+CME Error

Description

Stores into one of the two RAM profile mirrors the current AT configuration of the DCE interface in which the command is issued. The profile is selected according to the AT command parameter value. For more details on the AT command configuration saved in the profiles, refer to Section B.1.

Each AT interface has its own AT configuration in RAM mirror and NVM; the NVM is updated (if changed) when the command is issued. The command performes the storage of the configuration of all AT interfaces, regardless of the AT interface where it is issued. For more details about MUX channels personal profiles, see +CMUX notes.

Syntax

TypeSyntaxResponseExample

Action

AT&W[<value>]

OK

Defined values

ParameterTypeDescription

<value>

Number

  • 0 (default value): selects profile 0

  • 1: selects profile 1

Notes

  • Only <value>= 0 (default profile 0) is supported.

Display current configuration &V

&V

Modules

All products

Attributes

Syntax

PIN required

Settings saved

Can be aborted

Response time

Error reference

full

No

No

No

-

+CME Error

Description

Reports a summary of the current configuration and of the stored user profiles.

Syntax

TypeSyntaxResponseExample

Action

AT&V

List of commands stored in the active profile with the related values

OK

E: 0

Q: 0

+CREG: 0

+CEREG: 0

+CEDRXS: 0

+CSCON: 0

+CMGF: 1

+CTZR: 0

+CTZU: 1

+CMEE: 2

+UCESQS: 0,0

+CGEREP: 0

+UPSMR: 0

+USIMSTAT: 0

+UBIP: 0

+UPDPADDR URC: 0

+UPCFUN URC: 0

+CSMS: 0

+CSDH: 0

+USLPURC: "SLEEP1":0,"SLEEP2":0,"HIBNATE":0

&C: 0

&D: 2

+USMSFULL URC: 0

+CNEC: 0

&F: 0

&W: 0

&K: 3

&V: 1

OK

Notes

  • Only the active profile is displayed, without tags. The AT command does not show the stored profile.

  • AT&K setting is shown even if it is not part of the profile data that can be stored via AT&W.

Last updated: Jan 13, 2025
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