Campbell Scientific CR800 and CR850 Measurement and Control Systems - Manual (Page 68)

Section 5. System Overview
68
5.1.8.4 Data Format on Computer
CR800 data stored on a PC via support software is formatted as either ASCII or
Binary depending on the file type selected in the support software. Consult the
software manual for details on available data-file formats.
5.1.9 Communications
Read More! See Telecommunications and Data Retrieval
(p. 332).
The CR800 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. 334).
The CR800 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 CR800.
Communication can occur via RS-232, CS I/O, or digital I/O ports.
Advantages of PakBus:
• Simultaneous communication between the CR800 and other devices.
• Peer-to-peer communication — no PC required.
• Other PakBus dataloggers can be used as "sensors" to consolidate all data
into one CR800.
• Routing — the CR800 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 CR800 can talk to
another CR800 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 CR800, the datalogger support software
(p. 76)
must know the CR800
PakBus address. The PakBus address is changed using the external keyboard
/ display
(p. 382),
DevConfig utility
(p. 92),
CR800 Status table
(p. 506),
or PakBus
Graph
(p. 438)
software.