Panasonic KW9M Eco-POWER METER Modbus register map

Sources and notes

• KW9M Eco-POWER METER User's Manual
  Section 7.4.2, Data Register List (MODBUS communication)

Source: Panasonic KW9M Eco-POWER METER User's Manual, section 7.4 MODBUS (RTU) communication

• The meter leaves the factory set to MEWTOCOL: set Protocol (0x62) to MODBUS at the keys or with the Configurator before using this map; changing the protocol resets the serial settings.
• 32-bit values take two registers with the least significant word at the lower address (the manual marks the lower register <LSB>), so the word order is little; the bytes of each register are big-endian.
• The manual lists each measurement twice at different resolutions. This map uses the finer one (0.001 kWh, 0.001 kW, 0.01 V, 0.001 A, 0.01 Hz). The coarser mirrors start at 0x64 (energy, 0.01 kWh), 0x8C (power, 0.01 kW), 0xA4 (voltage, 0.1 V), 0xB4 (current, 0.01 A) and 0xBE (frequency, 0.1 Hz), and 0x145 to 0x158 repeat the total energies.
• The numbers in brackets, (1) to (3), are the measuring circuits or phases of the chosen wiring; with a single-phase two-wire meter only (1) is meaningful.
• Supported functions are 03 (read), 06 (write one register) and 16 (write several); a read is limited to 26 registers (57 bytes) and a write to 23 (55 bytes). Registers that are not listed read as 0 and writes to them are acknowledged but ignored, as are writes outside the setting range.
• Settings written over Modbus go to the internal memory straight away, which limits its life: do not rewrite them in a loop.
• Integral energies can be cleared by writing 0 to them or with the reset registers; the totals are read only. Instantaneous active and reactive powers are signed 32-bit values.
• The factory serial settings are device number 1, 19200 bit/s, 8 data bits, odd parity, 1 stop bit, response time 5 ms.