Modemulator User Guide
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Modemulator Memory
This section describes the types of memory that are included in the Courier Modemulator & M2M Gateway,
what the memory is used for, and where the memory is located.
The Modemulator Base Unit
The Courier Modemulator & M2M Gateway base unit contains Random Access Memory (RAM) and Flash
memory. These memories hold the operating system, radio firmware, system firmware, and application
software that control the operation of the base unit. The system firmware and the application software are
user-upgradable. See the
USR3520/USR803520 Gateway User Guide
for details on loading new system firmware and application software into the base unit.
The Modemulator Expansion Card
The USR3516-EMU expansion card that is installed into the Courier Modemulator & M2M Gateway contains
three types of memory that users can interact with: Random Access Memory (RAM), NonVolatile Random
Access Memory (NVRAM), and Flash memory.
Random Access Memory
The RAM holds the current settings that control the Modemulator card operation. These settings are
recalled from NVRAM and loaded into the RAM on power-up or when the Modemulator receives an
ATZ
command. Commands sent to the Modemulator to change settings will modify the RAM parameters only.
The settings must be saved into NVRAM to make the new settings nonvolatile. The commands to display
and manage the Modemulator card settings are detailed in the
this guide.
Nonvolatile Random Access Memory
The Modemulator card uses Electrically Erasable Programmable Read Only Memory (EEPROM) for
nonvolatile storage. This NVRAM is used to hold Modemulator card settings that are recalled to RAM on
power-up or when the Modemulator receives an
ATZ
command, and also holds the Modemulator card
dialing directory, security accounts, and security banners. The commands to display and manage the
Modemulator card NVRAM are detailed in the
Flash Memory
The Modemulator card firmware is stored in the Modemulator card Flash memory, which is another type of
nonvolatile storage. This firmware includes factory defaults that can be recalled by sending
AT&F0
,
AT&F1
, or
AT&F2
section in this guide for details. The
firmware stored in the Modemulator card Flash memory is user-upgradable. See
for details on loading new Modemulator card firmware into Flash memory.