CR1000 Manual - Campbell Scientific

Section 8. Operation
8.5 PakBus Overview
8.5.1 PakBus Addresses
8.5.2 Nodes: Leaf Nodes and Routers
of the query can be seen in the DevConfig and PakBusGraph settings
tables. SDC queries occur whether or not an SDC device is attached.
Read More! This section is provided as a primer to PakBus ® communications.
More information is available in PakBus Networking Guide, available at
www.campbellsci.com.
The CR1000 communicates with computers or other Campbell Scientific
dataloggers via PakBus ® . PakBus ® is a proprietary telecommunications protocol
similar in concept to IP (Internet protocol). PakBus ® allows compatible Campbell
Scientific dataloggers and telecommunications peripherals to seamlessly join a
PakBus ® network.
CR1000s are assigned PakBus ® address 1 as a factory default. Networks with
more than a few stations should be organized with an addressing scheme that
guarantees unique addresses for all nodes. One approach, demonstrated in figure
PakBus Network Addressing (p. 352) , is to assign single-digit addresses to the first
tier of nodes, double-digit to the second tier, triple-digit to the third, etc. Note that
each node on a branch starts with the same digit. Devices, such as PCs, with
addresses greater than 4000 are given special administrative access to the network
PakBus addresses are set using DevConfig, PakBusGraph, CR1000 Status table,
or with an external keyboard / display. DevConfig (Device Configuration Utility)
is the primary settings editor for Campbell Scientific equipment. It requires a
hardwire RS-232 connection to a PC and allows backup of settings on the PC hard
drive. PakBusGraph is used over a telecommunications link to change settings,
but has no provision for backup.
Caution Care should be taken when changing PakBus ® addresses with
PakBusGraph or in the Status table. If an address is changed to an unknown
value, a field visit with a laptop and DevConfig may be required to discover the
unknown address.
• A PakBus ® network consists of two to 4093 linked nodes.
• One or more leaf nodes and routers can exist in a network.
• Leaf nodes are measurement devices at the end of a branch of the PakBus ®
web.
o Leaf nodes can be linked to any router.
o A leaf node cannot route packets but can originate or receive them.
• Routers are measurement or telecommunications devices that route packets to
other linked routers or leaf nodes.
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