Chapter 3 – AT Commands, S-Registers, and Results Codes
Multi-Tech Systems, Inc. MT2834ZDX User's Guide 12
Command: $Hn Help Screens
Values: n = 1, 2, or 3
Default: None
Description: $H1 Display Help Screen #1.
$H2 Display Help Screen #2.
$H3 Display Help Screen #3.
Command: In Inquire Product Codes
Values: n = 0, 1, or 2
Default: None
Description: I0 Display modem ID number.
I1 Display firmware version number.
I2 Display modem description.
Command: $Jn Display Parity Bit
Values: n = 0, 1
Default: 0
Description: The $J command allows the parity bit to be seen when XON/OFF flow control is enabled (see the
&E command.)
$J0 disables the display of the parity bit to be seen when XON/XOFF flow control is enabled.
$J1 enables the display of the parity bit to be seen when XON/XOFF flow control is enabled.
Command: Ln List Commands
Values: n = 0, 5–8
Default: None
Description: L List stored telephone numbers.
L5 List current operating parameters.
L6 List current S-register values.
L7 List additional current operating parameters.
L8 List DSP code version number, processor speed, and online diagnostic parameters.
L9 List signal strength information.
L10 List signal to noise ratio information (SNR).
L11 List noise information.
Note: For L9, L10, and L11, you must first type +++AT<CR> (online escape command while
maintaining command mode), then type the command prefixed by an AT (e.g., ATL10).
Command: #Ln V.42 Mode Selection in Originate Mode
Values: n = 0, 1, 2, or 3
Default: 0
Description: #L0 Modems negotiate V.42 mode.
#L1 MNP on & LAP-M off.
#L2 LAP-M on & MNP off.
#L3 Disable detection phase and go directly to LAP-M.
Command: Mn Modem Speaker Control
Values: n = 0, 1, 2, or 3
Default: 1
Description: M0 Speaker always off.
M1 Speaker on until carrier signal detected.
M2 Speaker always on.
M3 Speaker on during dialing, off during handshaking.