0.2.0

Adds support for the Victron P1Link.

Supported devices

Device	Notes
VM-3P75CT	Three-phase energy meter (the default in the examples)
VM-3P5A	Three-phase energy meter
P1Link	Smart meter reader

What it reads

• Voltage, current and power per phase, plus total power
• Forward and reverse energy, in total and per phase
• Grid frequency and PE-N voltage on the VM-3P75CT and the VM-3P5A, with the fine-resolution frequency register where the device has one
• Device identity: product ID, serial number and hardware revision

Behaviour worth knowing

• Unavailable readings are None. A value the device reports as invalid, for example from a phase that has nothing connected, is returned as None, never as a number.
• Phases that aren't wired are left out. The meter's phase configuration is read once, and readings for phases it isn't connected to are not requested.
• Timeouts are retried. A request that gets no answer is retried up to three times with a one-second timeout, so one lost UDP packet doesn't turn into a failed update.
• Any transport. The library is built on modbus-connection, so it works over whatever backend you give it. The cli extra installs a UDP backend for the command-line example.

Installation

pip install victron-modbus

For the command-line example in script/query.py:

pip install "victron-modbus[cli]"

Usage

from modbus_connection.tmodbus import connect_udp
from victron_modbus.vm_3p75ct import VM3P75CT

connection = await connect_udp("192.168.1.101")
try:
    device = VM3P75CT(connection.for_unit(1))
    report = await device.async_update()  # which sub-systems updated / failed
    print(device.info.serial_number, device.power.total, device.phase_1.voltage)
finally:
    await connection.close()

Check report.failed before using the values. If you don't know the model up front, async_identify returns the matching device object. See the README for the full documentation.

Tested on

VM-3P75CT, VM-3P5A and P1Link devices.

Changes since 0.1.0

• Added the P1Link (victron_modbus.p1link, product ID 0xC02F).

0.1.0

First release of victron-modbus, an asynchronous, transport-independent Python library for reading Victron Energy devices over Modbus.

Supported devices

Device	Notes
VM-3P75CT	Three-phase energy meter (the default in the examples)
VM-3P5A	Three-phase energy meter

What it reads

• Voltage, current and power per phase, plus total power
• Forward and reverse energy, in total and per phase
• Grid frequency, using the fine-resolution register where the device has one
• Device identity: product ID, serial number and hardware revision

Behaviour worth knowing

• Unavailable readings are None. A value the device reports as invalid, for example from a phase that has nothing connected, is returned as None, never as a number.
• Phases that aren't wired are left out. The meter's phase configuration is read once, and readings for phases it isn't connected to are not requested.
• Timeouts are retried. A request that gets no answer is retried up to three times with a one-second timeout, so one lost UDP packet doesn't turn into a failed update.
• Any transport. The library is built on modbus-connection, so it works over whatever backend you give it. The cli extra installs a UDP backend for the command-line example.

Installation

pip install victron-modbus

For the command-line example in script/query.py:

pip install "victron-modbus[cli]"

Usage

from modbus_connection.tmodbus import connect_udp
from victron_modbus.vm_3p75ct import VM3P75CT

connection = await connect_udp("192.168.1.101")
try:
    device = VM3P75CT(connection.for_unit(1))
    report = await device.async_update()  # which sub-systems updated / failed
    print(device.info.serial_number, device.power.total, device.phase_1.voltage)
finally:
    await connection.close()

Check report.failed before using the values. A reading the device reports as unavailable is None. If you don't know the model up front, async_identify returns the matching device object. See the README for the full documentation.

Tested on

VM-3P75CT and VM-3P5A meters.