Campbell RF410 Manual de Instruções descarregar pdf (Página 63)

PakBus Networking Guide

7.4.4.2 Manual

To manually reset a device’s neighbor list, you can send a program to a

datalogger with the desired potential neighbor list in the program (see Edlog

PakBus Settings section of this guide).

7.4.5 Hello Exchange

A Hello Exchange is the way two devices are established as neighbors.

When a network device beacons, any non-neighbor CRxxxPB device within

range responds after a random delay of 1 to 4 seconds by sending a hello

command (09) packet to the beaconing device. The beaconing device answers

back with a hello response (89). In this manner the beaconing device and the

responding devices are established as neighbors. At this point, after a random

delay of 1 to 32 seconds, both network routers send their neighbor lists to their

neighbor routers allowing all network routers to quickly obtain neighbor lists

from every other router.

If a beaconing router has multiple neighbors, it may take more than one beacon

to discover them all. The hello responses to a beacon take only 30 milliseconds

or so at 9600 baud, but a collision could sometimes occur. If so, the next

beacon will probably successfully discover those devices.

If a device hears a (directed) message addressed to it, whose source is not in its

neighbor list, it will initiate a hello message to the source device if a neighbor

filter does not prevent it.

If LoggerNet is beaconing and the responding device is a CR205, after some

low level exchanges LoggerNet sends it a 09 hello command packet.. The

CR205 responds with an 89 hello response indicating a 0 (infinite)

communications verification interval. This way LoggerNet will keep the CR205

in its neighbor list until LoggerNet’s routing table is reset.

A Hello exchange also passes hop metrics, communications verification

intervals, and router indication (true/false). After a hello exchange both

neighbors use the smaller of the two CVIs that were passed to calculate the 2.5

× CVI to check for neighbor response.

The Hello Exchange is conducted at the highest possible priority so that it will

complete ahead of or at the same time as the get and send neighbor list

transactions.

Example 1 – LoggerNet (ffe) is beaconing and CR10XPB (001) is in-range.

LoggerNet broadcast beacon:

14:17:20.978 T bd bd bd bd bd bd bd 8f ff

8f fe 0f ff 0f fe e6 60 bd

CR10XPB sends hello command to LoggerNet:

14:17:23.821 R bd af fe f0 01 0f fe 00 01 09 fb 01 01 ff ff 82 7a bd

LoggerNet sends hello response to CR10XPB:

14:17:23.821 T bd a0 01 3f fe 00 01 0f fe 89 fb 01 03 00 1e 01 4b bd

1 2 ... 58 59 60 61 62 63 64 65 66 67 68 ... 123 124

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Campbell RF410 Manual de Instruções Página 63