Logical Devices

Logical devices are virtual devices available in powermanager. They can be used to setup certain calculations, formulas and derive measurement values from physical devices. These devices are used to calculate average, convert energy to power, power to energy, calculate key performance indicators (KPIs) and energy consumption.

The following types of logical devices are available in powermanager:

Average Value

The average value device is a logical device, which enables the user to calculate the average value of measurement point over a specific time period. You can configure an average value device to calculate values over hours, minutes, or seconds.

After configuring an average value device, the user can monitor, represent, and archive the average value calculated by the device.

 

Calculations with an average value device are delayed by fifteen seconds.
This device supports other properties in addition to powermanager properties.

 

Calculation Value

A calculation value device is a logical device, which allows the user to create and evaluate arithmetic or Boolean expressions. Variables are assigned to measurement points from devices and can be used to perform any of these operations. These arithmetic and Boolean expressions are evaluated when one of the measurement point (variable) value present in the expression changes, and the result is updated into the logical device. A measurement point used in a calculation value device cannot be added as a source measurement point to the same device, but can be added as source measurement point to other calculation value devices.

 

Calculations with a calculation value device are delayed by fifteen seconds.
This device supports other properties in addition to powermanager properties.

 

Converter

A converter is a logical device which helps the user to convert the power values to corresponding energy values over a given interval of time or vice versa. Once a converter device is configured, the user can monitor and archive either the power or energy values calculated.

During conversion the unit of the converted values will be derived as follows.

  • kWh unit is derived from kW unit or vice versa
  • varh unit is derived from var unit or vice versa
  • kVAh unit is derived from kVA unit or vice versa

 

Calculations with a converter are delayed by fifteen seconds.

 

KPI

A Key Performance Indicator is a measurable value that demonstrates how effectively a company is utilizing energy. Using this device you can generate the Key Performance Indicators (KPI) of any building or industry. A KPI (Key Performance Indicator) device allows the user to custom-define KPIs. The user can define how the KPI is calculated. KPIs can be calculated according to time ranges like 15 Minutes, Hourly, Weekly, Monthly and Yearly.

For every new KPI that is added, the user can use all elements for the calculation. There is the possibility to either calculate with measurement point elements, static values and variable that can be edited globally, e.g. numbers of employees, square meters, etc.

 

Calculations with an KPI device are delayed by fifteen seconds.
This device supports other properties in addition to powermanager properties.

 

Virtual Counter

The Virtual Counter is used to calculate the consumption values such as active energy, reactive energy and universal counter from a physical device or another virtual counter device.

For example, consider a scenario wherein a system consists of an incomer connected to two outgoing feeders and the energy meters are only available at the incomer one of the outgoing feeders. You can calculate the energy values of the outgoing feeder without the energy meter, by configuring the virtual counter accordingly.

 

Calculations with a virtual counter device are delayed by fifteen seconds.