Multi-Tech Systems MTA128NT - Manual (Page 15)

Configuration Utilities
MTA128ST/NT 15
V.120 Protocol—Similar to V.110 protocol, but provides rates up to 64000 bps on each B channel.
X.75 Protocol—Packet-switched network protocol for international use. Layer 2 portion of this protocol is
used commonly as a rate adaption protocol.
MLPPP Protocol—MLPPP (Multi-Link PPP) protocol provides rates up to 64 Kbps per channel. This
protocol uses both B channels at once, providing an aggregate data transmission speed of 128 Kbps.
Dialing Numbers ______________________________
The MTA128ST/NT can dial telephone number
n, where n can be up to 20 characters.
AT command: Dn (n = phone number).
Stored Numbers ______________________________
The MTA128ST/NT can store as many as ten phone numbers, up to 20 characters each.
AT command: &Z=
Dialing Stored Numbers _______________________
The MTA128ST/NT can dial a number previously stored in directory number
n with the &Zn=x command.
AT command: e.g., DS3
COM Port Settings
COM port settings control how your TA communicates with your computer through the RS232/V.24 serial
port.
Baud Rate or Bit Rate _________________________
Select the initial speed at which your TA communicates with your computer. For V.110 data protocol, the
rates must be identical on the local and remote TAs and may not exceed 38400 bps. For all other data
protocols (V.120, MLPPP, X.75, etc.), the default initial baud rate is 115200 bps. Typically, in command
mode, the MTA128ST/NT selects a serial port speed of 300, 1200, 2400, 4800, 9600, 19200, 38400,
57600, 115200, or 230400 bps depending on how fast the AT commands are coming from the computer or
terminal. The $SBn command sets the default serial speed used when the TA first powers up. Using the
%S command you can disable automatic speed selection and lock the serial port speed to 460800 bps.
See Serial Port Configuration Commands in Chapter 4 for more information.
AT commands: $SB or %S
Note: Your computer must have a high speed serial port with a 16550AFN UART, or equivalent, to utilize
ISDN’s high speeds.
Flow Control _________________________________
Select the method by which your TA and computer control the flow of data between them. Unless you know
your computer has special requirements, select the default RTS/CTS method. The other choice is XON/
XOFF.
AT command: &E
Data Bits, Parity, and Stop Bits __________________
These settings further control initial communications between the TA and computer. Unless you know your
computer has special requirements, use the default settings of 8 data bits, no parity checking, and 1 stop
bit (8-N-1). The TA sets these parameters automatically the first time it receives an AT command from the
computer.
AT commands: @P4=, @P3=, @P6=
DTR Detect Time ______________________________
Sets the time, in 0.1-second increments, that DTR must remain low before the TA disconnects. The default
value is 0.5 second; however, you can set it anywhere within the range 0–255
(0.05–25.5 seconds).
AT command: S25=
DCD Drop Time _______________________________
Sets the time, in 0.1-second increments, that a carrier must be lost before the TA disconnects. The default
value is 0.7 seconds; however, you can set it anywhere in the range 0–254 (0–25.4 seconds). Setting DCD
Drop Time to 255 causes the TA not to disconnect with loss of carrier when DCD Control is set to
Momentary Drop.
AT command: S10=