python-energymeter/energymeter.py

#!/usr/bin/env python3

"""
EnergyMeter: A Python module for interfacing with several energy meters.
"""

__author__  = 'Stan Janssen'
__email__   = 'stanjanssen@finetuned.nl'
__url__     = 'https://finetuned.nl/'
__license__ = 'Apache License, Version 2.0'

__version__ = '1.2.0'
__status__  = 'Beta'

import random
import socket
import struct
import asyncio
import time
import minimalmodbus
import tinysbus
from collections import Iterable

DEBUG = False

class ModbusTCPMeter:
    """
    Implementation for a Modbus TCP Energy Meter.
    """
    def __init__(self, port, tcp_port=502, slaveaddress=126, type=None, baudrate=None):
        self.port = port
        self.tcp_port = tcp_port
        self.device_id = slaveaddress

    def read(self, regnames=None):
        if regnames is None:
            registers = self.REGS
            return self._read_multiple(registers)

        if type(regnames) is str:
            registers = [register for register in self.REGS if register['name'] == regnames]
            return self._read_single(registers[0])

        if type(regnames) is list:
            registers = [register for register in self.REGS if register['name'] in regnames]
            return self._read_multiple(registers)

    def _read_single(self, register):
        message = self._modbus_message(start_reg=register['start'], num_regs=register['length'])
        data = self._perform_request(message)
        return self._convert_value(data, signed=register['signed'], decimals=register['decimals'])

    def _read_multiple(self, registers):
        registers.sort(key=lambda reg: reg['start'])
        results = {}
        for reg_range in self._split_ranges(registers):
            first_reg = min([register['start'] for register in reg_range])
            num_regs = max([register['start'] + register['length'] for register in reg_range]) - first_reg
            message = self._modbus_message(start_reg=first_reg, num_regs=num_regs)
            data = self._perform_request(message)
            results.update(self._interpret_result(data, reg_range))
        return results

    def _split_ranges(self, registers):
        """
        Generator that splits the registers list into continuous parts.
        """
        reg_list = []
        prev_end = registers[0]['start'] - 1
        for r in registers:
            if r['start'] - prev_end > 1:
                yield reg_list
                reg_list = []
            reg_list.append(r)
            prev_end = r['start'] + r['length']
        yield reg_list


    def _modbus_message(self, start_reg, num_regs):
        transaction_id = random.randint(1, 2**16 - 1)
        return struct.pack(">HHHBBHH", transaction_id,
                                       self.PROTOCOL_CODE,
                                       6,
                                       self.device_id,
                                       self.FUNCTION_CODE,
                                       start_reg - self.REG_OFFSET,
                                       num_regs)

    def _perform_request(self, message):
        if self.device is None:
            self._connect()
        self.device.send(message)
        data = bytes()
        expect_bytes = 9 + 2 * struct.unpack(">H", message[-2:])[0]
        attempt = 1
        while len(data) is not expect_bytes:
            time.sleep(0.05)
            data += self.device.recv(2048)
            if attempt >= 10:
                return 2 * struct.unpack(">H", message[-2:])[0] * [0]
            attempt += 1
        return data[9:]

    def _interpret_result(self, data, registers):
        """
        Pull the returned string apart and package the data back to its
        intended form.

        Arguments:
            * data: list of register values returned from the device
            * registers: the original requested set of registers

        Returns:
            * A dict containing the register names and resulting values

        """
        first_reg = min([register['start'] for register in registers])

        results = {}
        for register in registers:
            regname = register['name']
            start = (register['start'] - first_reg) * 2
            end = start + register['length'] * 2
            values = data[start:end]
            results[regname] = self._convert_value(values=values,
                                                   signed=register['signed'],
                                                   decimals=register['decimals'],
                                                   isFloat=register['isFloat'])
            if regname == "power_factor_total" and results[regname] == 0:
                results[regname] = 1    # The SMA will send out a 0 when the power factor is 100%
        return results

    def _convert_value(self, values, signed=False, decimals=0, isFloat=False):
        """
        Convert a list of returned integers to the intended value.

        Arguments:
            * bytestring: a list of integers that together represent the value
            * signed: whether the value is a signed value
            * decimals: number of decimals the return value should contain
            * isFloat: whether the valie is a float

        """
        numberOfBytes = len(values)
        formatcode_o = '>'

        if isFloat:
            formatcode_o += 'f'

        elif numberOfBytes == 1:
            if signed:
                formatcode_o += "b"
            else:
                formatcode_o += "B"

        elif numberOfBytes == 2:
            if signed:
                formatcode_o += "h"
            else:
                formatcode_o += "H"

        elif numberOfBytes == 4:
            if signed:
                formatcode_o += "l"
            else:
                formatcode_o += "L"


        value = struct.unpack(formatcode_o, bytes(values))[0]

        if value in self.NULLS:
            return None
        else:
            return float(value) / 10 ** decimals

    def _connect(self):
        self.device = socket.create_connection(address=(self.port, self.tcp_port))


class SMAMeter(ModbusTCPMeter):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

    REGS = [
            {'name': 'current_ac', 'start': 40188, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'current_l1', 'start': 40189, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'current_l2', 'start': 40190, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'current_l3', 'start': 40191, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'voltage_l1_l2', 'start': 40193, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'voltage_l2_l3', 'start': 40194, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'voltage_l3_l1', 'start': 40195, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'voltage_l1_n', 'start': 40196, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'voltage_l2_n', 'start': 40197, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'voltage_l3_n', 'start': 40198, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'active_power_total', 'start': 40200, 'length': 1, 'signed': True, 'decimals': -1},
            {'name': 'frequency', 'start': 40202, 'length': 1, 'signed': False, 'decimals': 2},
            {'name': 'apparent_power_total', 'start': 40204, 'length': 1, 'signed': True, 'decimals': -1},
            {'name': 'reactive_power_total', 'start': 40206, 'length': 1, 'signed': True, 'decimals': -1},
            {'name': 'power_factor_total', 'start': 40208, 'length': 1, 'signed': True, 'decimals': 3},
            {'name': 'active_export', 'start': 40210, 'length': 2, 'signed': False, 'decimals': 3},
            {'name': 'dc_power', 'start': 40217, 'length': 1, 'signed': False, 'decimals': -1},
            {'name': 'temperature_internal', 'start': 40219, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'temperature_other', 'start': 40222, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'operating_status', 'start': 40224, 'length': 1, 'signed': False, 'decimals': 0}
           ]

    REG_OFFSET = 1
    PROTOCOL_CODE = 0
    FUNCTION_CODE = 3
    NULLS = [2**16 - 1, 2**15 - 1, 2**15, -2**15]


class MulticubeMeter(ModbusTCPMeter):
    """
    Implementation for a Multicube energy meter over Modbus TCP.
    """
    def __init__(self, port, tcp_port=1502, slaveaddress=1, type=None, baudrate=None, auto_scale=True):
        super().__init__(port, tcp_port, slaveaddress, type, baudrate)
        self.device = socket.create_connection(address=(port, tcp_port))
        self.device_id = slaveaddress
        self.REGS = [
            {'name': 'energy_scale', 'start': 512, 'length': 2, 'decimals': 0, 'signed': True},
            {'name': 'active_net', 'start': 514, 'length': 2, 'decimals': 0, 'signed': True},
            {'name': 'apparent_net', 'start': 516, 'length': 2, 'decimals': 0, 'signed': True},
            {'name': 'reactive_net', 'start': 518, 'length': 2, 'decimals': 0, 'signed': True},
            {'name': 'active_power_total', 'start': 2816, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'apparent_power_total', 'start': 2817, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'reactive_power_total', 'start': 2818, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'power_factor_total', 'start': 2819, 'length': 1, 'decimals': 3, 'signed': True},
            {'name': 'frequency', 'start': 2820, 'length': 1, 'decimals': 1, 'signed': True},
            {'name': 'voltage_l1_n', 'start': 2821, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'current_l1', 'start': 2822, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'active_power_l1', 'start': 2823, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'voltage_l2_n', 'start': 2824, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'current_l2', 'start': 2825, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'active_power_l2', 'start': 2826, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'voltage_l3_n', 'start': 2827, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'current_l3', 'start': 2828, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'active_power_l3', 'start': 2829, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'power_factor_l1', 'start': 2830, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'power_factor_l2', 'start': 2831, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'power_factor_l3', 'start': 2832, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'voltage_l1_l2', 'start': 2833, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'voltage_l2_l3', 'start': 2834, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'voltage_l3_l1', 'start': 2835, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'current_n', 'start': 2836, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'amps_scale', 'start': 2837, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'phase_volts_scale', 'start': 2838, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'line_volts_scale', 'start': 2839, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'power_scale', 'start': 2840, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'apparent_power_l1', 'start': 3072, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'apparent_power_l2', 'start': 3073, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'apparent_power_l3', 'start': 3074, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'reactive_power_l1', 'start': 3075, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'reactive_power_l2', 'start': 3076, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'reactive_power_l3', 'start': 3077, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'peak_current_l1', 'start': 3078, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'peak_current_l2', 'start': 3079, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'peak_current_l3', 'start': 3080, 'length': 1, 'decimals': 0, 'signed': True},
            {'name': 'current_l1_thd', 'start': 3081, 'length': 1, 'decimals': 3, 'signed': True},
            {'name': 'current_l2_thd', 'start': 3082, 'length': 1, 'decimals': 3, 'signed': True},
            {'name': 'current_l3_thd', 'start': 3083, 'length': 1, 'decimals': 3, 'signed': True}
           ]
        if auto_scale:
            self.set_scaling()

    def set_scaling(self):
        """
        Call this function before reading anything to set up the correct scaling for this meter.
        """
        decimals_mapping = {1: 2, 2: 1, 3: 0, 4: -1, 5: -2, 6: -3, 7: -4}

        a_registers = ['current_l1', 'current_l2', 'current_l3', 'current_n']
        scale = int(self.read('amps_scale'))
        for r in self.REGS:
            if r['name'] in a_registers:
                r['decimals'] = decimals_mapping[scale]

        pv_registers = ['voltage_l1_n', 'voltage_l2_n', 'voltage_l3_n']
        scale = int(self.read('phase_volts_scale'))
        for r in self.REGS:
            if r['name'] in pv_registers:
                r['decimals'] = decimals_mapping[scale]

        lv_registers = ['voltage_l1_l2', 'voltage_l2_l3', 'voltage_l3_l1']
        scale = int(self.read('line_volts_scale'))
        for r in self.REGS:
            if r['name'] in lv_registers:
                r['decimals'] = decimals_mapping[scale]

        p_registers = ['active_power_total',
                       'reactive_power_total',
                       'apparent_power_total',
                       'active_power_l1',
                       'active_power_l2',
                       'active_power_l3',
                       'apparent_power_l1',
                       'apparent_power_l2',
                       'apparent_power_l3',
                       'reactive_power_l1',
                       'reactive_power_l2',
                       'reactive_power_l3']
        scale = int(self.read('power_scale'))
        for r in self.REGS:
            if r['name'] in p_registers:
                r['decimals'] = decimals_mapping[scale]

        e_registers = ['active_net', 'apparent_net', 'reactive_net']
        decimals_mapping = {3: 3, 4: 2, 5: 1, 6: 0, 7: -1}
        scale = int(self.read('energy_scale'))
        for r in self.REGS:
            if r['name'] in e_registers:
                r['decimals'] = decimals_mapping[scale]

    REG_OFFSET = 0
    PROTOCOL_CODE = 0
    FUNCTION_CODE = 3
    NULLS = [2**16 - 1, 2**15 - 1, 2**15, -2**15]

class SaiaMeter:
    def __init__(self, port, baudrate=38400, slaveaddress=1, type=None, **kwargs):
        """ Initialize the ABBMeter object.

        Arguments:
            * port: a serial port (string)
            * baudrate: the baudrate to use (integer)
            * slaveaddress: the address of the modbus device (integer)
            * Specification of the type. Used to limit the registers to a specific set.

        Returns:
            * An ABBMeter object

        """
        self.instrument = tinysbus.Instrument(address=slaveaddress,
                                              serial_port=port,
                                              baudrate=baudrate,
                                              **kwargs)

    def read(self, regnames=None):
        """ Read one, many or all registers from the device

        Args:
            * regnames (str or list). If None, read all. If string, read
              single register. If list, read all registers from list.

        Returns:
            * If single register, it returns a single value. If all or list,
              return a dict with the keys and values.

        Raises:
            * KeyError, TypeError, IOError
        """
        if regnames is None:
            return self._batch_read(self.REGS)
        if type(regnames) is list:
            registers = [register for register in self.REGS if register['name'] in regnames]
            if len(registers) < len(regnames):
                regs_not_available = [regname for regname in regnames if regname not in \
                                      [register['name'] for register in self.REGS]]
                print("Warning: the following registers are not available on this device: " +
                      ", ".join(regs_not_available))
                print("The available registers are: %s" +
                      ", ".join(register['name'] for register in self.REGS))
            if len(registers) == 0:
                return {}
            registers.sort(key=lambda reg: reg['start'])
            return self._batch_read(registers)
        elif type(regnames) is str:
            registers = [register for register in self.REGS if register['name'] == regnames]
            if len(registers) == 0:
                raise ValueError("Register not found on device.")
            return self._read_single(registers[0])
        else:
            raise TypeError

    def _read_single(self, register):
        """
        Read a single register and return the value. Not to be called directly.

        Arguments:
        * register: a 'register' dict that contains info on the register.

        Returns:
        * The interpreted value from the meter.
        """

        if register['length'] == 1:
            return self.instrument.read_register(register_address=register['start'],
                                                 number_of_decimals=register['decimals'],
                                                 signed=register['signed'])
        if register['length'] == 2:
            value = self.instrument.read_long(register_address=register['start'],
                                              signed=register['signed'])
            return value / 10 ** register['decimals']

        if register['length'] == 4:
            value = self.instrument.read_registers(register_address=register['start'],
                                                   number_of_registers=register['length'])
            return self._convert_value(values=value,
                                       signed=register['signed'],
                                       number_of_decimals=register['decimals'])

    def _read_multiple(self, registers):
        """
        Read multiple registers from the slave device and return their values as a dict.

        Arguments:
            * A list of registers (complete structs)

        Returns:
            * A dict containing all keys and values
        """

        first_reg = min([register['start'] for register in registers])
        num_regs = max([register['start'] + register['length'] for register in registers]) - first_reg
        values = self.instrument.read_registers(register_address=first_reg,
                                                num_registers=num_regs)
        return self._interpret_result(values, registers)

    def _batch_read(self, registers):
        """
        Read multiple registers in batches, limiting each batch to at most 10 registers.

        Arguments:
            * A list of registers (complete structs)

        Returns:
            * A dict containing all keys and values
        """
        # Count up to at most 10 registers:
        start_reg = registers[0]['start']
        batch = []
        results = {}
        for register in registers:
            if register['start'] + register['length'] - start_reg <= 10:
                batch.append(register)
            else:
                results.update(self._read_multiple(batch))
                batch = []
                batch.append(register)
                start_reg = register['start']

        results.update(self._read_multiple(batch))
        return results

    def _interpret_result(self, data, registers):
        """
        Pull the returned string apart and package the data back to its
        intended form.

        Arguments:
            * data: list of register values returned from the device
            * registers: the original requested set of registers

        Returns:
            * A dict containing the register names and resulting values

        """
        first_reg = min([register['start'] for register in registers])

        results = {}
        for register in registers:
            regname = register['name']
            start = register['start'] - first_reg
            end = start + register['length']
            values = data[start:end]
            results[regname] = self._convert_value(values=values,
                                                   signed=register['signed'],
                                                   number_of_decimals=register['decimals'])
        return results

    def _convert_value(self, values, signed=False, number_of_decimals=0):
        """
        Convert a list of returned integers to the intended value.

        Arguments:
            * bytestring: a list of integers that together represent the value
            * signed: whether the value is a signed value
            * decimals: number of decimals the return value should contain
        """

        number_of_registers = len(values)
        formatcode_i = '>'
        formatcode_o = '>'

        if number_of_registers == 1:
            formatcode_i += "L"
            if signed:
                formatcode_o += "l"
            else:
                formatcode_o += "L"

        if number_of_registers == 2:
            formatcode_i += 'LL'
            if signed:
                formatcode_o += "q"
            else:
                formatcode_o += "Q"

        bytestring = struct.pack(formatcode_i, *values)
        value = struct.unpack(formatcode_o, bytestring)[0]

        return float(value) / 10 ** number_of_decimals

    REGS = [{'name': 'firmware_version',           'start': 0, 'length': 1, 'signed': True, 'decimals': 0},
            {'name': 'num_registers',              'start': 1, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'num_flags',                  'start': 2, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'baudrate',                   'start': 3, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'serial_number',              'start': 11, 'length': 2, 'signed': False, 'decimals': 0},
            {'name': 'status_protect',             'start': 14, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'sbus_timeout',               'start': 15, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'sbus_address',               'start': 16, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'error_flags',                'start': 17, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'tariff',                     'start': 19, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'active_import_tariff_1',     'start': 20, 'length': 1, 'signed': False, 'decimals': 2},
            {'name': 'resettable_active_import_t1','start': 21, 'length': 1, 'signed': False, 'decimals': 2},
            {'name': 'active_import_tariff_2',     'start': 22, 'length': 1, 'signed': False, 'decimals': 2},
            {'name': 'resettable_active_import_t2','start': 23, 'length': 1, 'signed': False, 'decimals': 2},
            {'name': 'voltage_l1_n',               'start': 24, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'current_l1',                 'start': 25, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'active_power_l1',            'start': 26, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'reactive_power_l1',          'start': 27, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'power_factor_l1',            'start': 28, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'voltage_l2_n',               'start': 29, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'current_l2',                 'start': 30, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'active_power_l2',            'start': 31, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'reactive_power_l2',          'start': 32, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'power_factor_l2',            'start': 33, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'voltage_l3_n',               'start': 34, 'length': 1, 'signed': False, 'decimals': 0},
            {'name': 'current_l3',                 'start': 35, 'length': 1, 'signed': False, 'decimals': 1},
            {'name': 'active_power_l3',            'start': 36, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'reactive_power_l3',          'start': 37, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'power_factor_l3',            'start': 38, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'active_power_total',         'start': 39, 'length': 1, 'signed': True, 'decimals': 2},
            {'name': 'reactive_power_total',       'start': 40, 'length': 1, 'signed': True, 'decimals': 2}]