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PN 88300150
$EB
Asynchronous Word Length Command
The MT2834MR has an 11-bit capability when operating asynchronously. The $EB command
selects between 11-bit and 10-bit operation. Type AT$EB1 to enable the modem to function
in an 11-bit (one start bit, eight information bits, one parity bit and one stop bit) format. Type
$EB0 (the default setting) to enable a 10-bit (one start bit, seven information bits, one parity
bit and one stop bit) format. $EB is functional in both Command and On-line mode. $EB0
automatically detects parity when an AT command is issued.
&M
Synchronous/Asynchronous Mode Switching
The &M command is used to set the on-line mode of the MT2834MR to either Synchronous
or Asynchronous. AT&M0 sets the mode to Asynchronous, and all communications will be
Asynchronous, both in On-line and Command mode. AT&M1 causes the MT2834MR to
communicate asynchronously when in Command mode, and to switch to synchronous mode
while on-line. The factory default setting is &M0.
&X
Synchronous Transmit Clock Select
The &X command selects the Synchronous Transmit Clock Source. External clocking is
when the DTE provides transmit clocking to the modem on pin 24 of the RS232C interface.
Internal clocking is when the modem provides transmit clocking to the DTE on pin 15 of the
RS232C interface. Internal clocking (&X0) is the factory default setting.
The command &X2 selects Slave (External) Clocking. The &X2 command causes the
MT2834MR to generate the Transmit Clock timing (pin 15) from the Receive Clock (pin 17)
from the DTE, (therefore 15 and 17 are the same). In Slave mode, all timing is controlled by
the receive clock. The position of pin 3 is insignificant when in Slave mode.
$AS
AS/400 Support
The MT2834MR has the ability to function in an IBM AS/400 environment. The $AS1
command enables AS/400 mode, and causes the MT2834MR function with the IBM
command set. The $AS0 command disables this function.
Note: The MT2834MR must have Command mode and Synchronous mode enabled to allow
AS/400 mode to be selected.
The factory default setting is AS/400 mode disabled ($AS0).
$SP
UNIX UUCP Spoofing
The MT2834MR can be configured for a UNIX environment that employs ACK flow control as
a means of monitoring data integrity. The modem can perform UUCP "spoofing", where the
MT2834MR can generate ACKs at the DTE interface. Data is transmitted more time
effectively because the delay of waiting for data to be received, then for an ACK to be
returned at the remote end, is eliminated. Type $SP1 to enable UNIX UUCP spoofing. Type
$SP0 to disable UNIX UUCP spoofing (the factory default setting). For more information on
the UUCP (UNIX-to-UNIX Copy Program) function, refer to your UNIX system
documentation.
&I
Inactivity Direction
You may use the &I command in conjunction with S-Register S30 to select how the Inactivity
Timer will work in your modem. &I controls the direction of the inactivity. S-Register S30
controls the duration of the inactivity. You may turn off the Inactivity Timer, or set the modem
to respond to inactivity only when receiving, or only when transmitting, or to respond to both
receiving and transmitting.
&I0
Turns off the Inactivity Timer.
4/3/01
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