User's Manual

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network timing and second, greatly reducing system power consumption by allowing the CPU to remain
inactive during the majority of the radio activity. The autonomous MAC, provides software independent
timing control of the radio and radio related functions, resulting in superior reliability and exceptionally
low power.
SECURITY
Network security is an often overlooked component of a complete network solution. Proper
implementation of security protocols is significant in terms of both engineering effort and market value
in an OEM product. WSM2400 system solutions provide a FIPS-197 validated encryption scheme that
includes authentication and encryption at the MAC and network layers with separate keys for each
mote. This not only yields end-to-end security, but if a mote is somehow compromised, communication
from other motes is still secure. A mechanism for secure key exchange allows keys to be kept fresh. To
prevent physical attacks, WSM2400 includes hardware support for electronically locking devices,
thereby preventing access to WSM2400’s flash and RAM memory and thus the keys and code stored
therein.
TEMPERATURE SENSOR
WSM2400 includes a calibrated temperature sensor on chip. The temperature readings are available
locally through WSM2400’s serial API, in addition to being available via the network manager. The
performance characteristics of the temperature sensor can be found in the Temperature Sensor
Characteristics section.
RADIO INHIBIT
The RADIO_INHIBIT input enables an external controller to temporarily disable the radio software
drivers (for example, to take a sensor reading that is susceptible to radio interference). When
RADIO_INHIBIT is asserted the software radio drivers will disallow radio operations including clear
channel assessment, packet transmits, or packet receipts. If the radio is active in the current timeslot
when RADIO_INHIBIT is asserted the radio will be disabled after the present operation completes. For
details on the timing associated with RADIO_INHIBIT, see the RADIO_INHIBIT AC Characteristics section.
FACTORY INSTALLED SO FTWARE
This product is provided with software programmed into the device. Devices can be configured via
either the CLI or API ports.