Electrical Meters – Modbus RTU and Pulse Output
Logic Beach offers two families of electrical meter transducers that readily interface to our data logging instruments. Depending on the model, the meter to data logger interface can be Modbus RTU and/or a simple Pulse output.
PowerScout: The PowerScout line of meters offers both Modbus RTU and Pulse outputs in a single unit.
Wattnode: The Wattnode line offers the WNC Modbus only output meters and the WNB Pulse only output meters. Specifics on Modbus RTU interface vs Pulse interface follow.
Modbus RTU Interface
For applications requiring detailed electrical power information with multiple electrical parameters, Logic Beach offers Modbus RTU enabled electrical parameter meters. These meters can measure electrical loads and provide multiple electrical parameters via a Modbus RTU interface including power (kW), energy (kWh), phase voltages, phase currents, power factor and much more.
The IntelliLogger family of data loggers configured as a Modbus RTU Master can interrogate and log user specified parameters from one or more connected Modbus RTU Slave power meters. Simultaneous with the readings logged via the Modbus interface, the IntelliLogger can be sampling, processing, logging and reporting hard-wired inputs (e.g. thermocouples, pressures, flows, etc) as well.
The Modbus RTU interface uses a two-wire serial RS-485 connection between the IntelliLogger and the meters. Each device (meter or other Modbus Slave device on the RS-485 network) is assigned a unique device address allowing up to 15 Modbus devices to be connected to a single IntelliLogger.
Details on the various Modbus connected multi-parameter meters follow. Additional details on Modbus and the Modbus option for the IntelliLogger data logging instrument family are available on the IntelliLogger Modbus Interface Options page.
Pulse Output Interface
For applications requiring only energy logging (kWh), electrical meters equipped with pulse outputs (instead of Modbus) can be utilized. Meters with pulse outputs output a switch closure “pulse” that corresponds to some unit of energy measured. By totalizing the pulses over a period of time (eg 15 minute utility intervals) and appropriate scaling within the Logic Beach logger, the energy usage can be profiled.
Additionally, Pulse Output meters can be used to garner instantaneous Power (demand) by measuring the frequency of the energy pulse output. Logic Beach data loggers can be readily programmed to perform the necessary calculations to determine instantaneous power from the Energy pulse output allowing two commonly desired electrical parameters to be logged from a single lower cost Pulse Output meter.
PowerScout – Universal Electrical Service with Modbus and Pulse Outputs Overview:
The PowerScout power meters are available in two major models… the PS3037 for single electrical service monitoring and the PowerScout 24 commonly used for sub-metering applications where up to 24 branch circuits can be monitored. The PowerScout line of meters is flexible in design in that a single model can be used on the full gamut of electrical service configurations (eg Wye and Delta) as well as a full range of service voltages from 80Vac to 600Vac.
PowerScout PS3037
The PowerScout 3037 is a revenue-grade, single-point 3-phase power meter that communicates with the Logic Beach data loggers via its Modbus RTU or Pulse output. The PowerScout Meter can monitor voltage, current, power, energy, and many other electrical parameters on single and three-phase systems. With the Modbus RTU interface option the IntelliLogger can be simply programmed to acquire readings from the PowerScout internal registers for use in the IntelliLogger Program Net. Users can simply select desired parameters to log.
All PowerScout 3037 models have a broadband power supply (80-600VAC) which allows them to operate on electrical services from 120Vac single phase to 480Vac 3phase. They can be paired with a variety of current transformers, from split cores that measure < 1A up to large RoCoils designed for measuring 4000A. In addition, communication protocols are field-selectable. Easily toggle between Modbus or BACnet using ViewPoint software.
The PowerScout 3037 is available with an optional LCD for viewing setup and real-time paraemters. Additiionally, it is available with RS-485 (for Modbus) and optionally Ethernet connectivity. All units have a pulse output that can be linked to various parameters (eg energy where each pulse corresponds to some user defined unit of energy).
The PowerScout can be used for temporary test applications such as energy audits or M&V studies or permanently installed for long term monitoirng, sub-metering, etc.
