Analog Inputs - ABB 615 Series Manual

Section 3
Vendor-specific implementation
3.2.3
16

Analog inputs

The following table lists analog inputs (object 30). It is important to note that 16 bit
and 32 bit variations of analog inputs are transmitted through DNP 3.0 as signed
numbers.
The original DNP 3.0 analog value is the same value as the IEC
61850 value generated for the same point. Measurands in IEC 61850
are expressed as floating point values while DNP 3.0 analog values
are integers. Therefore, it may be necessary to scale the original DNP
3.0 values in order to include possible decimals in the DNP 3.0 integer
value.
The deadband is not configured in DNP 3.0. It is configured at the device level. The
analog change events are therefore generated by the device functions, not DNP 3.0.
The analog change event time stamp will inherently be accurate and consistent with
the reporting of events though other channels, for example, LHMI, WHMI and other
communication protocols.
There are four scaling options associated with analog input reporting.
• None: the reported value is the process value.
• Multiplication: the process value is multiplied by a constant. An offset is added
producing the reported value.
• Division: the process value is divided by a constant. An offset is added producing
the reported value.
• Ratio:
• Configuration-time ratio scaling: Find R for new set of {in_min, in_max,
out_min, out_max} R = (out_max - out_min)/(in_max - in_min)
• Runtime ratio scaling: Reported value = (inval - in_min) * R + out_min
The analog input event buffer size is set 150.
Table 6: Analog inputs
Description
Static (steady-state) object number
Change event object number
Static variation reported when variation 0
requested (default setting)
Change event variation reported when variation 0
requested (default setting)
Values
30
32
3 (32 bit analog input w/o flag)
1 (32 bit analog change event w/o time)
Communication Protocol Manual
1MRS756709 A
615 series