Campbell Scientific CR1000 Measurement and Control System - Manual (Page 69)

Section 5. System Overview
69
The CR1000 communicates with external devices to receive programs, send data,
or act in concert with a network. The primary communication protocol is PakBus.
Modbus and DNP3 communication protocols are also supported. Refer to the
appendix Telecommunications Hardware
for information on available
communications devices.
5.1.9.1 PakBus
Read More! See PakBus Overview
(p. 351).
The CR1000 communicates with Campbell Scientific support software,
telecommunication peripherals, and other dataloggers via PakBus, a proprietary
network communications protocol. PakBus is a protocol similar in concept to IP
(Internet protocol). By using signatured data packets, PakBus increases the
number of communications and networking options available to the CR1000.
Communication can occur via RS-232, CS I/O, or digital I/O ports.
Advantages of PakBus:
• Simultaneous communication between the CR1000 and other devices.
• Peer-to-peer communication — no PC required.
• Other PakBus dataloggers can be used as "sensors" to consolidate all data
into one CR1000.
• Routing — the CR1000 can act as a router, passing on messages intended for
another logger. PakBus supports automatic route detection and selection.
• Short distance networks with no extra hardware —-a CR1000 can talk to
another CR1000 over distances up to 30 feet by connecting transmit, receive
and ground wires between the dataloggers. PC communications with a
PakBus datalogger via the CS I/O port, over phone modem or radio, can be
routed to other PakBus dataloggers.
• Datalogger to datalogger communications — special CRBasic instructions
simplify transferring data between dataloggers for distributed decision
making or control.
• In a PakBus network, each datalogger is set to a unique address before being
installed. The default PakBus address in most devices is 1. To communicate
with the CR1000, the datalogger support software
(p. 77)
must know the
CR1000 PakBus address. The PakBus address is changed using the external
keyboard / display
(p. 399),
DevConfig utility
(p. 92),
CR1000 Status table
(p. 528),
or PakBus Graph
(p. 461)
software.
5.1.9.2 Modbus
Read More! See Modbus
(p. 367).
The CR1000 supports Modbus master and Modbus slave communication for
inclusion in Modbus SCADA networks.
5.1.9.3 DNP3 Communication
Read More! See DNP3
(p. 364).