DNP3 I/O Addressing

Within VTS, DNP I/O addresses for all points except File Identifiers (object 70) are formatted in the following manner:

 

Obj/Var/Index[:NS | :LATCH | :PULSE]

 

Where:

•    Obj is the DNP object to use. A table of supported object types can be found later in this topic.

•    Var is the DNP variation of the object

•    Index is the points index.  For the Restart flag in the Internal Indications (object 80, var 1) use an index of 7.

•    :NS is used to indicate that the point should not be scanned, as its value will be updated either by a DNP event, or the background class 0 scan.  If this option isn’t specified, then the point will be scanned at the rate specified in the points scan rate field

•    :LATCH is used to indicate the output type is a latched control.  If this option isn’t specified the output type is a trip/raise or close/lower control

•    :PULSE is used to indicate the output type is a pulsed control.  If this option isn’t specified the output type is a trip/raise or close/lower control

 

Examples:

1)  To read a digital input with status (obj 1, var 2) at address 4321 use

            1/1/4321.

2)  To read a 32 bit delta counter without status (obj 20, var 7) at address 876 use

            20/7/876
3)  To write a latching digital output to off, (also known as a control relay output block)  (obj 12 ,var 1) at address 42 use

            12/1/42:LATCH

… sending a value less than 0.

 

For File Identifiers, I/O addresses are formatted in one of the two following manners:

On older systems, the following was in use:

70/1/Name[/Start/End/CP/DataType]

 

Where:

•    Name is the filename to use

•    Start is the starting record to use, 0 to 65535.  If not specified then 0 is used

•    End is the ending record to use, 0 to 65535.  If not specified, then 65535 is used

•    CP is a flag indicating that the Cooper Power non-standard Read (function code 0x01) and qualifier 0x5B should be used.  If not specified, then the default will be a Write (function code 0x02) and qualifier 0x1B

•    DataType indicates that a value of the specified type should be read from the offset specified by End of the record specified by Start. 

•    DataType has the values and meanings specified below:

 

 

On newer systems, the following object should be used. This reads the entire file in one operation.

70/5/File_Identifier

Where:

•    File_Identifier is the filename to use, including the path if required.  If the path begins with a slash, the address will look like:70/5//dir/dir/filename.dat. The exact form of the file identifier following 70/5/ will depend on your hardware.