DTE & DCE Interface AT Commands with Syntax

DTE stands for "Data Terminal Equipment" and DCE stands for "Digital Communication Equipment" and both are used in the interfacing of GSM modem. These DTE and DCE commands are used in various ways as some commands are used to set registers and some are used echo and suppression of code. We have collected set of these DTE and DCE commands with description and syntax which will help you in Using them. Subscribe to PLC, HMI Programming and SCADA Tutorials by Email .

DTE DCE Interface AT commands with Syntax

1. AT S: Set register

It is used to set a register which controls the operation of the DCE.

Syntax: AT S< reg id="" >= <reg value="" >


2. AT E: Command echo.

It is used to set whether or not the DCE echoes characters received from the DTE during command and online command state.

Syntax: AT E[<value >] (Values can be 0 and 1 for On and OFF)


3. AT Q: Result code suppression.
It is used to set whether or not the DCE transmits result codes to the DTE.

Syntax: AT Q[<value >] (Values can be 0 and 1 for On and OFF)


4. AT V: DCE response format.

It is used to set the contents of the header and trailer transmitted with result codes and information responses.

Syntax: AT V[<value >] (Values can be 0 and 1 for Numeric and Alphabet)


5. AT X: Result code selection and call progress monitoring control.

It is used to Set whether or not the DCE transmits particular result codes to the DTE.

Syntax: AT X[<value >]

Value can be as follows
0 -CONNECT, dial and busy disabled
1 -CONNECT , dial and busy disabled
2 -CONNECT , dial enabled, busy disabled
3 -CONNECT , dial disabled, busy enabled
4 -CONNECT , dial enabled and busy enabled



6. AT &C: Circuit 109 (Received line signal detector) behavior.

It Sets how the state of the DCD line relates to the detection of received line signal from distant end.

Syntax: AT &C[<value >] (Values can be 0 and 1 for always ON and in accordance with underlying DCE-default).


7. AT &D: Circuit 108 (Data terminal ready) behaviour.

It Determines how the DCE responds when circuit 108/2 (DTR) is changed from the ON to the OFF condition during online data state.

Syntax: AT &D[<value >]

Value can be
0 -ignored
1 -enters online command state and issues an OK result code, a call remains connected
2 -instructs the DCE to perform an orderly teardown of a call (default)


8. AT +IPR: Fixed DTE rate
It Specifies the data rate at which the DCE will accept commands.

Syntax: AT +IPR=< rate>
can be
decimal (0,300,1200,2400,4800,9600,19200); Bits per second
0 -auto bauding


9. AT +IFC: DTE-DCE local flow control

It Controls the operation of local flow control between the DTE and DCE during the data state.

Syntax: AT +IFC=[< >dce_by_dte>[,]]

Values can be
dce_by_dte: decimal (0-2); Flow control of data received from DCE
0 -None
1 -SW (XON/XOFF)
2 -HW (RTS/CTS) (default)

: decimal (0-2); Flow control of data transmitted to DCE
0 -None
1 -SW (XON/XOFF)
2 -HW (RTS/CTS) (default)



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