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PakBus Networking Guide

3.4 Beaconing vs. Neighbor Filter Hello

Once you have chosen the collection approach and communication devices for

your PakBus network, you need to provide a way for the PakBus devices to

discover in-range devices. Some PakBus devices function as routers and, as

such, are responsible to know the best route to every PakBus device in the

network. The first step is for routers to discover their own neighbors. Next, they

share their neighbor lists with all other routers in the network. End of the line

“Leaf node” devices don’t normally beacon or hello.

Discovery is done by:

• Neighbor Filter hello-ing

• Beaconing

• A combination of beaconing and hello-ing

• P190, P191, P192, P196, P198 or P224 peer-to-peer communications

• LoggerNet device map

The P193 instruction does not initiate communications and so cannot be relied

upon to discover neighbors.

A device with neighbor filter has a potential neighbor list where the user lists

the device addresses that the router attempts to discover by sending directed

hellos. Other in-range PakBus devices are thus filtered out so they can’t

become neighbors. If you have two in-range routers using neighbor filters, in

order for them to discover one another you must list each of them as a potential

neighbor in the other’s neighbor filter.

A beaconing device broadcasts to all neighboring PakBus devices. Any device

within range, that has no neighbor filter to prevent it, will respond and become

a “neighbor” to the beaconing device. If the beaconing device is LoggerNet, all

in-range PakBus devices will respond (with or without neighbor filter).

Sometimes a simple way to discover other PakBus devices is to set up a

beacon, however, a neighbor filter works better in most situations. This is

particularly true of rf networks where beaconing can result in marginal links,

whereas a neighbor filter approach for your routers forces them to use strong rf

links (see Quick Start and Forced Routing sections).

LoggerNet is able to discover an in-range PakBus device at connect time using

the ‘static route’ from its device map (no beaconing or hello filter required).

In addition to the discovery of neighbors, the above methods are also used to

maintain ongoing lists of viable routes.

3.4.1 CR200 Series

CR200 Series devices, which don’t already have a neighbor, respond to a

beacon after waiting a random 0 to 1 seconds, by sending a hello-request

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Campbell RF410 Bedienerhandbuch Seite 32