SKF CMWA 8800, Service Manual, Page: 14 / 104

The Basics
The Network
8 SKF Wireless Machine Condition Sensor
Service Manual
The Network
WirelessHART Terminology
HART7 (spec155) added the Wireless command set, including network security terms
such as Network ID and 32 character Join Key, and advertisement. HART7 is backward
compatible. Some terms commonly used with WirelessHART networks are defined
below.
Term Definition
Advertisement
Messages sent by the network manager to announce the network’s
existence.
Block transfer
Generally, HART communications are connectionless transactions.
Block transfer extends the protocol to support connection oriented
reliable stream service for large data blocks. Used for sending
waveforms and firmware upgrades.
Burst mode
The sensor publishes data for any of the HART commands at a
regular interval. Contrary to polling, no query is made so burst
mode is more efficient.
Caching
Burst data for a query are saved in gateway memory. When
queried by the host software, the gateway will return the cache
data instead of polling the data from the sensor.
Fast pipe
This is a single device mode which establishes a direct connection
to a selected device. It has four times the transfer rate of a regular
connection. The network manager in the gateway grants fast pipe
mode only to devices which identify themselves as high power
profile devices.
This can be selected manually in the gateway’s
Operating Modes
web page or automatically by the network manager during block
transfer for waveform upload or firmware download. See the
section
Full Routing vs. Leaf Node , Power profile .
Network manager
Responsible for the coordination of communication between the
devices and the gateway and between devices.
Leaf node device
A device that does not participate in the mesh network. It does not
“help its neighbor.”
Link
The full communication specification between adjacent nodes in
the network; the communication parameters necessary to move a
packet one hop.
Long tag HART7 32-character logical name for the HART device.
P1 profile
256 slot superframe, 2.56 sec cycle; normal battery life, normal
join process, better user interface response .
P1 can be selected during your interaction with the P+F web page
to speed response time. Then, when you are finished, P2 can be
selected for normal network operation to conserve battery life.