DNP3 Master

The DNP3 Master driver is used to communicate via TCP/IP with RTUs, PLCs, or Intelligent Electronic Devices (IEDs) such as Protection Relays that support the DNP3 (Distributed Network Protocol).

These settings determine how the SCADA (Master) exchanges data with the field device (Outstation). This protocol is widely utilized in the Power/Energy and Water Automation sectors.

Connection Parameters

Parameter	Description	Example Value
IP Address	The IP address of the remote device (RTU/PLC) to communicate with.	192.168.0.10
Port	The standard TCP port for DNP3 is 20000.	20000
Settings	A data string containing protocol-specific advanced settings. Clicking this field opens the “DNP3 Master Dialog” for detailed configuration.	[“NORMAL”,”1″,”60″,…]

DNP3 Master Dialog Settings

This window contains settings for timing, retries, and data class management for the DNP3 protocol.

Parameter	Description	Options / Default
Logging Level	Determines the detail level of background logs. “NORMAL” is recommended unless troubleshooting.	NORMAL (Default), ALL, APP_COMMS, NONE
Channel Retry Min.	Minimum wait time (seconds) before attempting to reconnect after a link failure.	1
Channel Retry Max.	Maximum limit for the reconnection wait time (seconds). The system increases the wait time exponentially between failed attempts up to this limit.	60
Local Address	Master ID: The address of the SCADA system within the DNP3 network.	1
Remote Address	Outstation ID: The DNP3 address of the target RTU or PLC.	100
Keep Alive Timeout (s)	Frequency of TCP-level “Keep Alive” packets sent to verify link integrity.	30
Time Sync. Mode	The method the Master (SCADA) uses to synchronize the Slave device’s clock.	NonLAN: Standard (for high-latency networks). LAN: Precision (for local networks). None: No sync.
Disable Unsol On Startup	If checked, automatically disables the device’s ability to send unsolicited messages when the connection is first established.	Checked (Enabled)
Unsol Class Mask	Defines which data classes are permitted to send “Unsolicited” messages.	AllClasses: Immediate updates for Class 1, 2, 3. AllEventClasses: Event data only. None: Polling only.
Startup Integrity Class Mask	Defines which classes the Master reads completely (Integrity Poll) upon initial connection.	AllClasses (Rec.): Full sync (Class 0,1,2,3). AllEventClasses: Event classes only.
Integrity On Event Overflow	Determines if SCADA initiates an “Integrity Poll” when the device’s event buffer is full. Critical for preventing data loss.	Checked (Enabled)
Event Scan On Events Available	Defines which classes to read when the device raises the “Events Available” flag.	None (Common): Used if Unsolicited is ON. AllEventClasses: Scans Classes 1, 2, 3.
Poll Period (ms)	General Poll: The frequency at which SCADA periodically reads data from the device (Class 0 Poll).	1000 ms
Control Qualifier Mode	Defines the index size used when sending commands (Write). Legacy devices may require 1-byte indexes.	Always Two Bytes: Standard/Secure. Allow One Byte: For legacy devices.
Response Timeout (s)	Maximum time to wait for a response from the device after a request is sent.	5
Task Retry Period (s)	Wait time before retrying a timed-out or failed task.	5
Task Start Timeout (s)	Maximum time a task can wait in the queue before starting.	10

Addressing Format and Data Types

When creating tags in Wise SCADA, the following abbreviations are used for DNP3 data groups:

Group No	Data Type Definition	Wise SCADA Tag	Usage Purpose
1 / 2	Binary Input	B	Digital inputs (Open/Closed)
3	Double-bit Input	DBB	Two-bit states (Trip/Close/Fault)
30	Analog Input	A	Measurements (Temp, Pressure, etc.)
20	Counter	C	Counter data (Energy Pulse, etc.)
10	Binary Output Status	BOS	Feedback for digital outputs
40	Analog Output Status	AOS	Feedback for setpoints
110	Octet String	OS	Text-based data