Campbell CR850, Operator'S Manual, Page: 347 / 566

Section 8. Operation
347
Note Setting the encryption key for a PakBus port device will force all messages
it sends to use encryption.
8.6 Alternate Telecommunications
The CR800 communicates with datalogger support software
(p. 76)
and other
Campbell Scientific dataloggers
(p. 541)
using the PakBus
(p. 438)
protocol ( PakBus
Overview
(p. 334)
). Modbus, DNP3, and Web API are also supported. CAN bus is
supported when using the Campbell Scientific SDM-CAN communications
module.
8.6.1 DNP3
8.6.1.1 Overview
The CR800 is DNP3 SCADA compatible. DNP3 is a SCADA protocol primarily
used by utilities, power-generation and distribution networks, and the water- and
wastewater-treatment industry.
Distributed Network Protocol (DNP) is an open protocol used in applications to
ensure data integrity using minimal bandwidth. DNP implementation in the
CR800 is DNP3 Level-2 Slave Compliant with some of the operations found in a
Level-3 implementation. A standard CR800 program with DNP instructions will
take arrays of real time or processed data and map them to DNP arrays in integer
or binary format. The CR800 responds to any DNP master with the requested data
or sends unsolicited responses to a specific DNP master. DNP communications
are supported in the CR800 through the
RS-232 port,
COM1
or
COM2
, or over
TCP, taking advantage of multiple communications options compatible with the
CR800, e.g., RF, cellular phone, satellite. DNP3 state and history are preserved
through power and other resets in non-volatile memory.
DNP SCADA software enables CR800 data to move directly into a database or
display screens. Applications include monitoring weather near power transmission
lines to enhance operational decisions, monitoring and controlling irrigation from
a wastewater-treatment plant, controlling remote pumps, measuring river flow,
and monitoring air movement and quality at a power plant.
8.6.1.2 Programming for DNP3
CRBasic example Implementation of DNP3
(p. 349)
lists CRBasic code to take
Iarray() analog data and Barray() binary data (status of control port 5) and map
them to DNP arrays. The CR800 responds to a DNP master with the specified
data or sends unsolicited responses to DNP Master 3.
8.6.1.2.1 Declarations
Table DNP3 Implementation — Data Types Required to Store Data in Public
Tables for Object Groups
(p. 348)
shows object groups supported by the CR800
DNP implementation, and the required data types. A complete list of groups and
variations is available in
CRBasic Editor Help for DNPVariable() .