Value points

If scaling is required:

Point: Value_Object_Index

Location1 = ID

Location2 = DNP Object Index

Location3 = DNP Slave Address

Location4 = Scanclass is solicited. Zero if unsolicited.

Location5 = DNP Object Type

InstrumentTag = DNP Object Variation

Convers = See explanation below for details.

Span = See explanation below for details.

Squareroot = See explanation below for details.

UserReal1 = See explanation below for details.

UserReal2 = See explanation below for details.

Zero = See explanation below for details.

All data coming from a DNP 3.0 compliant device is one of four types; binary, 8-bit status, 16-bit integer, or 32-bit integer. The PI DNP3 interface supports scaling the 16-bit and 32-bit integer types. The scaling for these types adheres to one of the following formulas depending on the value of the PI point squareroot attribute.

The following definitions describe the different variables of the formula:

• Value is the 16 or 32-bit value received from the RTU

• def_range is the default range and is equal to 65,536 (216) for 16-bit values and 4,294,967,296 (232) for 32-bit integer/short float values. Long float (64-bit real) values received from the RTU will be treated the same as 32-bit values due to limitations of the operating system.

• def_min is the default minimum and it is equal to is -32,768 (-215) for 16-bit values and -2,147,483,648 (-231) for 32-bit integer/short float values. Long float (64-bit real) values received from the RTU will be treated the same as 32-bit values due to limitations of the operating system.

• instr_min is the instrument zero and is found in the PI point UserReal1 attribute

• instr_range is the instrument range and is equal to the PI point UserReal2 attribute

• pispan is equal to the PI point attribute span

• pizero is equal to the PI point attribute zero