Simply Modbus

Simply Modbus This is Modbus monitoring software for the PC. Simply Modbus $60 For Modbus RTU master $60 For Modbus TCP client/master Modbus monitoring, logging Pros All Modbus setup is done from one screen, so it’s simple to configure. It has fewer settings than Modscan32, which also simplifies configuration. It has a “Send” button to […]


PortMon Overview PortMon is a (Mark Russinovich’s) utility currently available as a free download from the Sysinternals web site is used for monitoring Windows kernel-level I/O packets sent/received between serial port device drivers and Win32, Modbus Master software applications such as Modscan32. It shows the timestamped data that Modbus devices send and receive as […]

Photovoltaic and Wind Power Applications

Photovoltaic and Wind Power Applications How to use the WattNode Modbus registers for a PV or wind power application. For many power and energy monitoring applications, two Modbus commands are sufficient to acquire basic readings from the WattNode®. The first command reads registers 1201-1221 which include: PowerA to PowerC: the instantaneous power readings. VoltA to […]

Modbus Message Timing

Modbus Message Timing With the Modbus RTU protocol, the start of a message begins with the first byte sent after a minimum silent interval (i.e. ~2 ms. at 19200 baud or ~3.6 ms. at 9600 baud). To strictly conform to the standard, the maximum time between sending any two successive bytes that belong to […]

WattNode Modbus - Option TTL

WattNode Modbus – Option TTL Option TTL factory configures the WattNode® Modbus meter for a 5-Volt logic level communications interface. This is a special order item. Contact the factory for availability and price. This option eliminates the need for extra circuitry (RS485 or RS232 transceiver ICs) when the master host device is only equipped with […]

BACnet and Modbus Energy Resolution

BACnet and Modbus Energy Resolution Overview The WattNode® BACnet and Modbus meters (WNC series) measures energy once per second in raw units. The raw measurements are then scaled based on the meter’s calibration, the nominal line voltage, and the current transformer (CT) rated amps. Finally, the result is added to a 64 bit energy accumulator. […]

WNC Modbus Customer Questions

WNC Modbus Customer Questions This page lists customer questions about the WattNode® Modbus® meter and how they were answered or resolved. The most common customer problems with the Modbus WattNode result from configuration problems with the Modbus master. Registers are sometimes documented with leading “3”s or “4”s to indicate holding or input registers. This results […]

WattNode Modbus

WattNode® Modbus® Power and Energy Meters AC Power Measurement for Modbus Networks: Real Power (kW) and Energy (kWh)Bi-directional Net MeteringReactive Power (VAR)Power FactorsIndividual Phase Measurements WattNode Energy Meters for BACnet The WattNode Modbus is a kilowatt hour (kWh) energy and power meter that communicates on a EIA RS-485 network, measures 1, 2, or 3 phases [...]

Floating Point Register Details for WattNode Modbus

Floating Point Register Details for the Modbus WattNode I'm writing software to communicate with the WattNode. How do I interpret the float registers? An IEEE-754 single-precision (32-bit) float converter can help. Here are links to a couple of converters: - convert hex into decimal float and vice versa If you enter a value [...]