DNP 3.0

DNP 3.0 (Distributed Network Protocol 3.0) is a communication protocol primarily used in the industrial automation field, especially in power systems for supervisory control and data acquisition (SCADA) systems. It enables reliable data exchange between remote terminal units (RTUs) and master station systems.

Device Settings

Field	Description
host	Device IP address
port	Device port number, default 20000
masterid	Master station ID, default 1
slaveid	Slave station ID, default 2
class0123_interval	Class0123 pull interval, default 20000 ms
class123_interval	Class123 pull interval, default 1000 ms
time_sync	Time synchronization, default No

Supported Data Types

• uint8
• uint16
• int16
• uint32
• int32
• float
• bit

Address Format

obj.var.index(.attribute)

CROB.index:counter:on-time:off-time

obj and var

In the DNP 3.0 protocol, obj and var are used to define an object type, and index specifies a specific object within a group of objects. The attribute currently only supports value. If not specified, the default is value.

Currently supported objects are as follows:

obj	var	Object	r/w	Type
1	1	binary input	r	bit
1	2	binary input with status	r	bit
2	1	binary input change without time	r	bit
2	2	binary input change with absolute time	r	bit
2	3	binary input change without relative time	r	bit
10	1	binary output	r	bit
10	2	binary output with status	r	bit
10	3	binary output change with time	r	bit
20	1	32-bit binary counter with flag	r	uint32/int32
20	2	16-bit binary counter with flag	r	uint16/uint16
20	5	32-bit binary counter without flag	r	uint32/int32
20	6	16-bit binary counter without flag	r	uint16/int16
21	1	32-bit frozen binary counter	r	uint32/int32
21	2	16-bit frozen binary counter	r	uint16/int16
30	1	32-bit analog input	r	uint32/int32
30	2	16-bit analog input	r	uint16/int16
30	3	32-bit analog input without flag	r	uint32/int32
30	5	32-bit float analog input	r	float
32	1	32-bit analog input change without time	r	uint32/int32
32	2	16-bit analog input change without time	r	uint16/int16
32	3	32-bit analog input change with time	r	uint32/int32
32	4	16-bit analog input change with time	r	uint16/int16
32	7	32-bit float analog input change with time	r	float
40	1	32-bit analog output	r	uint32/int32
40	2	16-bit analog output	r	uint16/int16
40	3	32-bit float analog output	r	flaot
41	1	32-bit analog output block	w	uint32/int32
41	2	16-bit analog output block	w	uint16/int16
41	3	32-bit float analog output block	w	float
42	7	32-bit float analog output event with time	r	float

CROB (Control Relay Output Block) is a special object associated with actuating on/off type output devices, write-only, type uint8, because it requires setting counter, on-time, and off-time in addition to Control Code.

Control Code values are as follows:

Control Code	Action
1	output pluse on
2	output pluse off
3	output latch on
4	output latch off
65	output pluse on + close
66	output pluse off + close
67	output latch on + close
68	output latch off + close
129	output pluse on + trip
130	output pluse off + trip
131	output latch on + trip
132	output latch off + trip
+16	+ queue
+32	+ clear

Address Examples

Address	Data Type	Description
1.2.0	bit	Value of binary input index 0
1.2.1	bit	Value of binary input index 1
2.2.1	bit	Value of binary input index 1 with absolute timestamp
CROB.0:0:0:0	bit	Control binary output index 0 output
40.1.0	bit	Value of 32-bit binary output index 0