value, the set of supported values is presented as a list of the parenthetically-enclosed value
range strings described above, separated by commas. For example, the information text in
response to testing an action that accepts three sub parameter, and supports various ranges for
each of them, could appear as follows:
(0),(1-3),(0,4-6,9,11-12)
This indicates that the first sub parameter accepts only the value 0, the second accepts any
value from 1 through 3 inclusive, and the third sub parameter accepts any of the values 0, 4, 5,
6, 9, 11, or 12.
3 Data Command Set
3.1 Command Guidelines
The commands used to control and report modem operation in data modem mode are defined
in this section.
The Data Modem Mode commands and responses described in this section are applicable
when cFCLASS=0. (See +FCLASS in Section 3.2.1 for the definition of the
FCLASS command.)
The default values are typical of a fully configured modem supporting all data rates and
options. The actual default value is dependent upon modem software as defined by the .INF File.
Commands are accepted by the modem once the previous command has been fully executed,
which is normally indicated by the return of an appropriate result code. Execution of
commands D and A, either as a result of a direct command or a re-execute command, will be
aborted if another character is entered before completion of the handshake.
3.1.1 Escape Code Sequence
When the modem has established a connection and has entered on-line data mode, it is
possible to break into the data transmission in order to issue further commands to the modem
in an on-line command mode. This is achieved by the DTE sending to the modem a sequence
of three ASCII characters specified by register S2. The default character is '+'. The maximum
time allowed between receipt of the last character of the three escape character sequence from
the DTE and sending of the OK result code to the DTE is controlled by the S12 register.
3.2 Data Commands
The modem will respond to the commands detailed below. Parameters applicable to each
command are listed with the command description. The defaults shown correspond to default
values provided in the .INF File.
3.2.1 Generic Modem Control
Z - Reset to Default Configuration
This command instructs the modem to reset to default values as altered by non-volatile
parameter storage. If the modem is connected to the line, it will be disconnected from the line,
terminating any call in progress.
All of the functions of the command are completed before the modem issues the result code.
The DTE should not include additional commands on the same command line after the
Z
command because such commands are ignored.
Syntax
Z
Result Code
OK
+FCLASS - Select Active Service Class
This command selects the active service class (mode).
