The Modbus sub-meter is a kilowatt hour (kWh) energy and power meter that communicates on a EIA RS-485 network, measures 1, 2, or 3 phases with voltages from 120 to 600 volts Vac and currents from 5 to 6,000 amps in delta (phase to phase) and wye (phase to neutral) configurations.
Communication
Protocol: Modbus RTU (binary)
Baud Rates: 2,400, 4,800, 9,600,19,200, and 38,400 baud
Duplex: Half (two-wire plus common)
Parity (default): N81 (no parity, eight data bits, one stop bit)
Modbus Buffer: 256 bytes
Response Time (typical): 5 to 25 milliseconds
Electrical
Line powered
Operating Voltage Range: –20% to +15% of nominal
Power Line Frequency: 50 or 60 Hz
CT Input: 0.333 Vac nominal, 0 to 0.5 Vac operating, 3 Vac maximum