Campbell CR800 Specifications Page 296

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Section 14. PakBus Networking
14-12
14.3.2 PakBus Devices
A PakBus device is one that is capable of creating and processing PakBus
packets. Examples of PakBus devices are: the CR800, LoggerNet, the RF401
(in PakBus Node protocol), the CR10X with PakBus OS, the NL100, and the
CR206.
A PakBus device has an integer PakBus address (PBA) from 1 to 4094. In
order for a network to function properly, each PakBus device must have a
unique PakBus address. By default the LoggerNet server has PBA 4094 which
is used by all device map PakBusPorts. A CR800’s default PakBus address is
1.
The CR800, by default, handles networks of up to 50 nodes. If the number of
PakBus devices in your network exceeds this number you will have to change
the CR800’s PakBus Nodes Allocation setting to accommodate the greater
number.
14.3.3 Neighbor Discovery
The terms neighbor and discover have special meaning in PakBus. In order for
two PakBus devices (for example, LoggerNet and a CR800 linked by a pair of
RF401s) to transfer data or programs, the two devices must first become
neighbors. To become neighbors, one PakBus device must discover the other
by sending it a low-level (PakCtrl) hello packet. Upon receiving it the other
must answer back with a hello-response packet. If this hello-exchange
succeeds, the two devices are established as neighbors.
If two PakBus devices need to communicate via router or routers (for example,
LoggerNet and CR800_20 below), then for each link in the route between the
devices (there might be two, three, or more links) the two devices associated
with each link must establish themselves as neighbors by successful hello-
exchanges in a continuous chain in order to have BMP5 communications (i.e.,
clock checks, program sends, data collections, etc.) between the end devices.
neighbors
neighbors
neighbors
link 3
~~~~~~
link 2
~~~~~~
link 1
~~~~~~
PC (LoggerNet)
RF401
CR800_10
RF401
CR800_20
RF401
RF401
Stand-alone
Router
There are two main approaches to neighbor discovery –
beaconing neighbor filter helloing
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