15
CHAPTER 4: Operation
• Stored Configuration S-Registers
Stored configuration S-Registers
are kept in
nonvolatile memory
;
the register values are stored in a
semiconductor random access
memory (RAM) chip that retains
the informa-tion even when the
modem loses power. So if the
modem’s batteries wear down,
the power adapter is unplugged,
or the power outlet fails, the
stored configuation S-Registers
remember their contents.
When the modem powers up it
loads the current S-Register
configuration with the stored
configuration.
Use the AT commands discussed
at the beginning of this chapter
to store your current
configuration to the stored
configuation, or to load the
current configuration with the
stored configuration.
• Factory Configuration S-
Registers
These registers are factory-set
choices for the modem; they
form a “default” configuration.
These values are permanently
stored in a “read only memory”
(ROM) semiconductor chip.
