User's Manual

Chapter Four Configuration
Man_905UD_2.0.doc Page 27
Before a 905U-D unit will accept Hayes commands, it must be in configuration mode. A
host device may force the unit to configuration mode by sending three “escape” characters -
“+++”. The default escape character is “+”, however this may be changed as it is one of the
configuration parameters Note that in the Host-connect operating modes, the 905U-D units
start up in configuration mode. These modes (0, 1, 2 or 3) simulate the operation of
telephone or leased-line modems, and may be used with standard host software designed
with Hayes command control.
Once in configuration mode, the 905U-D unit will accept a string of Hayes commands, and
the configuration changes made. The changes will not however be stored in permanent
memory (EEPROM) unless the Hayes command for recording the configuration (AT&W) is
sent. When the configuration changes are made, the module must be put back into its
operating mode by using the “online” Hayes command, ATO
The 905U-D will automatically change from configuration mode to operating mode if there
has been no AT command entry within a certain time. This time is one of the configuration
parameters.
The following Hayes commands are accepted by the 905U-D unit :
4.3.1 Unit Reset
The ATZ command resets the unit as if power had been switched off and on. After power up,
the configuration will be the last saved configuration - that is, the last configuration saved by
the AT&W command.
4.3.2 Storing Configuration Parameters - Write Registers
Once configuration parameters have been changed, they can be stored to non-volatile
memory with the AT&W command. When the unit is reset from power up or via the ATZ
command, the stored parameters are restored.
4.3.3 Default Values - Restore Factory Defaults
The AT&F command will reset the configuration parameters to the default values. To reset
the values and save them to nonvolatile memory, use AT&F&W
Refer to Appendix A section 1.1.10 for using the configuration switches to reset to factory
defaults.
4.3.4 S-Registers
The E405 provides 15 S-Registers to configure the operation of the unit. S-Registers may be
read using the Hayes command ATSn = xxx, where n is the number of the configuration
parameter, and xxx is the value shown below for each parameter. The entire configuration
parameters may be viewed by the Hayes command AT&V.
The configuration parameters and values are :