PACSystems™ RX3i DNP3 Outstation User Manual
Section 1
GFK-3103B
June 2020
Introduction
2
1.3
Glossary
ACTIVE Unit
Primary unit in HSB configuration from which all the communications occur
Analog Output Value
Data Object
A means by which the DNP3 Master Station can set an analog value at the Outstation. The
CPE400/CPL410 Outstation supports signed 16-bit and 32-bit data, as well as 32-bit PLC Real
variables.
BACKUP Unit
Secondary unit in HSB configuration, which is synchronized with Primary unit
Class 0 Data Poll or
Integrity Poll
A request from a master station to an Outstation for all the data for all points, Data Object
Group 60, Variance 1.
Class 1, 2, or 3 Data
Poll or Event Poll
A request from a master station to an Outstation for the event data which is stored in the
Outstation, typically with time and status information. This data can be further organized by
groups, representing the class number. Specifying the Class Number ensures that only those
points that are part of the group are returned. The DNP3 Outstation groups digital data into
class 1 and analog data into class 2 by default.
CROB Data Object
A Control Relay Output Block (Data Object Group 12, Variance 1) is the method used to set a
bit in the PLC from a Master Station. It represents a physical action of Select Before Operate
(SBO) for an Outstation to set a bit over DNP3.
DNP
Distributed Network Protocol
DNP3
Specific implementation of DNP
Flags
Indicators that are returned to the Master Station from the Outstation, in general to describe
point-related conditions which may exist at the Outstation.
Group
A specification sub-group of Object that refers specifically to a data type, point action, or
Outstation action as defined in the DNP3 Specification. Group is a macro sub-category of
Object and is unique when describing DNP3 Objects.
HSB
Hot Standby System
IIN Bits
Indicators that are returned to the Master Station from the Outstation, in general to describe
conditions that are not point-related which may exist at the Outstation.
IPv4
Internet Protocol version 4 (IPv4) is the fourth version in the development of the Internet
Protocol (IP), and routes most traffic on the Internet. IPv4 is described in IETF publication RFC
791.
LAN
Local Area Network
LLA
The Link Layer Address of a DNP3 node, sometimes called its station address.
Master
DNP3 Master communicating with the Outstation
NASU
Non-synchronized ACTIVE Unit