Ametek TR-2100 Operation Manual page 90

TR-2100 User Manual
Analogue Inputs
Analogue Inputs are implemented as Object 30 Var 4 (16-bit analogue input without flag)
points. A total of 160 points are implemented, which represent:
• Analogue Voltage values, 1 per analogue channel
• Analogue Profile values, 4 per analogue channel (Pre-fault, Immediate, Final, Post-
Clearance)
The Analogue Voltage and the Analogue Profile points use different formulae to calculate
actual engineering units.
Analogue Voltage Point Indices
The 32 Analogue Voltage inputs (Point Indices 1 through 32) are scaled so that 32,768 bits
represent the recorder's full-scale input value. To convert the DNP output to actual
engineering units, use the following formula.
=
Actual Primary Units
Where:
- DNP raw value is the number output from the DNP port
- FSD is the full scale primary RMS value (voltage or current)
Example:
The raw value read from Analogue Channel 1 is 19640, and your FSD is 345 kV. Multiply
345000 by square root 2 to obtain the peak voltage, then divide by 32768 bits to obtain Units
Per Bit. Multiply the Units Per Bit by 19640 to obtain the actual primary voltage reading.
Analogue Profile Point Indices
The Analogue Profile points (Point Indices 110 through 429) are scaled so that 16,384 bits
represent the full-scale value. To convert the DNP output to actual engineering units, use
the following formula.
=
Actual Primary Units
DNP raw value x
345000 x 2
x 19640
32768
DNP raw value x
(FSDx ) 2
32768
=
292432 . 47 volts
FSD
16384
84