25
SECTION VI: Other Functions
Resetting Modbus Registers
Many of the PowerScout
™
registers are real-time values such as instantaneous watts or power factor.
However, some registers are accumulated values such as kWh, kVARh, kVAh and various Peak Demand
(kW) values.
Accumulating registers can be reset using the ViewPoint
™
Read/Write Registers
screen.
1.
In the data entry box next to the
Set Modbus Register
button, enter or select 44066. This is
modbus register, Reset Acc Measurements.
2.
In the
To Value
box type 1234.
3.
Click the
Set Modbus Register
button. The accumulating registers are reset to 0.
The tables in Appendix E list all of the data registers available on the PowerScout. Note that following
the modbus protocol, the actual register address requested is offset from the base modbus register by
40001.
Data Scaling – Interpreting the PowerScout Registers
The use of modbus protocols limits the data registers to a maximum of two bytes (16 bits) or a
maximum decimal value of 65535. Modbus requires that the data be unsigned (positive) integer values.
To overcome these limitations some measured (and stored) values must be
scaled
to fit into the modbus
registers. The raw value read from the modbus registers is multiplied by a scalar to convert the raw
data. The following table lists the data scalars and the respective values for the PowerScout.
Data Scalar
Scalar Value
kW/kWh
Demand
kVAR/kVARh
kVA/kVAh
Power
Factor
Amps
Volts
0
.00001
.00001
.00001
.01
.01
.1
1
.001
.001
.001
.01
.1
.1
2
.01
.01
.01
.01
.1
.1
3
.1
.1
.1
.01
.1
.1
4
1
1
1
.01
1
1
5
10
10
10
.01
1
1
≥6
100
100
100
.01
1
1
Table IV-1: Data Scalars and Values for Registers 44001 thru 44061
The data scalar is stored in register 44602.
When selecting a data scalar, the following guidelines need to be considered:
•
If the data scalar selected is too low, an incorrect data result is returned from the register.
•
If the data scalar selected is too high, the significant digits following the decimal point are
removed.
Содержание PowerScout 3
Страница 19: ...15 Figure IV 1 Single Phase Two Wire N white L1 black L2 red L3 blue ...
Страница 20: ...16 Figure IV 2 Single Phase Three Wire N white L1 black L2 red L3 blue ...
Страница 21: ...17 Figure IV 3 Three Phase Three Wire Delta N white L1 black L2 red L3 blue ...
Страница 22: ...18 Figure IV 4 Three Phase Four Wire Wye N white L1 black L2 red L3 blue ...
Страница 23: ...19 Figure IV 5 Three Phase Four Wire Delta N white L1 black L2 red L3 blue ...
