GE MiCOM P747 Agile, Technical Manual

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8 DNP 3.0
This section describes how the DNP 3.0 standard is applied to the Px40 platform. It is not a description of the
standard itself. The level at which this section is written assumes that the reader is already familiar with the
DNP 3.0 standard.
The descriptions given here are intended to accompany the device profile document that is included in the
Menu Database document. The DNP 3.0 protocol is not described here, please refer to the documentation
available from the user group. The device profile document specifies the full details of the DNP 3.0
implementation. This is the standard format DNP 3.0 document that specifies which objects; variations and
qualifiers are supported. The device profile document also specifies what data is available from the device
using DNP 3.0. The IED operates as a DNP 3.0 slave and supports subset level 2, as described in the
DNP 3.0 standard, plus some of the features from level 3.
The DNP 3.0 protocol is defined and administered by the DNP Users Group. For further information on
DNP 3.0 and the protocol specifications, please see the DNP website (www.dnp.org).
8.1 PHYSICAL CONNECTION AND LINK LAYER
DNP 3.0 can be used with three physical layer protocols: EIA(RS)232, EIA(RS)485, or Ethernet.
Several connection options are available for DNP 3.0
● Rear Port 1 (RP1) - for permanent SCADA connection via RS485
● Optional fibre port (RP1 in slot A) - for permanent SCADA connection via optical fibre
● Optional Rear Port 2 (RP2) - for permanent SCADA connection via RS485 or RS232
● An RJ45 connection on an optional Ethernet board - for permanent SCADA Ethernet connection
● A fibre connection on an optional Ethernet board - for permanent SCADA Ethernet connection
The IED address and baud rate can be selected using the front panel menu or by the settings application
software.
When using a serial interface, the data format is: 1 start bit, 8 data bits, 1 stop bit and optional configurable
parity bit.
8.2 OBJECT 1 BINARY INPUTS
Object 1, binary inputs, contains information describing the state of signals in the IED, which mostly form part
of the digital data bus (DDB). In general these include the state of the output contacts and opto-inputs, alarm
signals, and protection start and trip signals. The ‘DDB number’ column in the device profile document
provides the DDB numbers for the DNP 3.0 point data. These can be used to cross-reference to the DDB
definition list. See the relevant Menu Database document. The binary input points can also be read as
change events using Object 2 and Object 60 for class 1-3 event data.
8.3 OBJECT 10 BINARY OUTPUTS
Object 10, binary outputs, contains commands that can be operated using DNP 3.0. Therefore the points
accept commands of type pulse on (null, trip, close) and latch on/off as detailed in the device profile in the
relevant Menu Database document, and execute the command once for either command. The other fields
are ignored (queue, clear, trip/close, in time and off time).
There is an additional image of the Control Inputs. Described as Alias Control Inputs, they reflect the state of
the Control Input, but with a dynamic nature.
● If the Control Input DDB signal is already SET and a new DNP SET command is sent to the Control
Input, the Control Input DDB signal goes momentarily to RESET and then back to SET.
● If the Control Input DDB signal is already RESET and a new DNP RESET command is sent to the
Control Input, the Control Input DDB signal goes momentarily to SET and then back to RESET.
MiCOM P747 Chapter 7 - SCADA Communications
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