SmlLib

A SML (Smart Message Language) library

About

This library can be used to parse SML byte streams. It does not read from external devices.

Usage

The sml2mqtt program makes use of this library.

Example:

from smllib import SmlStreamReader

stream = SmlStreamReader()
stream.add(b'BytesFromSerialPort')
sml_frame = stream.get_frame()
if sml_frame is None:
    print('Bytes missing')

# Add more bytes, once it's a complete frame the SmlStreamReader will
# return the frame instead of None
stream.add(b'BytesFromSerialPort')
sml_frame = stream.get_frame()

# A quick Shortcut to extract all values without parsing the whole frame
# It's faster but in rare cases this might raise an exception (e.g. InvalidBufferPos).
# In that case you have to use sml_frame.parse_frame() which is guaranteed to work
obis_values = sml_frame.get_obis()

# return all values but slower
parsed_msgs = sml_frame.parse_frame()
for msg in parsed_msgs:
    # prints a nice overview over the received values
    print(msg.format_msg())

# In the parsed message the obis values are typically found like this
obis_values = parsed_msgs[1].message_body.val_list

# The obis attribute of the SmlListEntry carries different obis representations as attributes
list_entry = obis_values[0]
print(list_entry.obis)            # 0100010800ff
print(list_entry.obis.obis_code)  # 1-0:1.8.0*255
print(list_entry.obis.obis_short) # 1.8.0

SmlMessage
    transaction_id: 17c77d6b
    group_no      : 0
    abort_on_error: 0
    message_body <SmlOpenResponse>
        codepage   : None
        client_id  : None
        req_file_id: 07ed29cd
        server_id  : 11111111111111111111
        ref_time   : None
        sml_version: None
    crc16         : 25375
SmlMessage
    transaction_id: 17c77d6c
    group_no      : 0
    abort_on_error: 0
    message_body <SmlGetListResponse>
        client_id       : None
        sever_id        : 11111111111111111111
        list_name       : 0100620affff
        act_sensor_time : 226361515
        val_list: list
            <SmlListEntry>
                obis           : 8181c78203ff (129-129:199.130.3*255)
                status         : None
                val_time       : None
                unit           : None
                scaler         : None
                value          : ISK
                value_signature: None
                -> (Hersteller-Identifikation)
            <SmlListEntry>
                obis           : 0100000009ff (1-0:0.0.9*255)
                status         : None
                val_time       : None
                unit           : None
                scaler         : None
                value          : 11111111111111111111
                value_signature: None
                -> (Geräteeinzelidentifikation)
            <SmlListEntry>
                obis           : 0100010800ff (1-0:1.8.0*255)
                status         : 386
                val_time       : None
                unit           : 30
                scaler         : -1
                value          : 123456789
                value_signature: None
                -> 12345678.9Wh (Zählerstand Total)
            <SmlListEntry>
                obis           : 0100010801ff (1-0:1.8.1*255)
                status         : None
                val_time       : None
                unit           : 30
                scaler         : -1
                value          : 123456789
                value_signature: None
                -> 12345678.9Wh (Zählerstand Tarif 1)
            <SmlListEntry>
                obis           : 0100010802ff (1-0:1.8.2*255)
                status         : None
                val_time       : None
                unit           : 30
                scaler         : -1
                value          : 0
                value_signature: None
                -> 0.0Wh (Zählerstand Tarif 2)
            <SmlListEntry>
                obis           : 0100100700ff (1-0:16.7.0*255)
                status         : None
                val_time       : None
                unit           : 27
                scaler         : 0
                value          : 555
                value_signature: None
                -> 555W (aktuelle Wirkleistung)
            <SmlListEntry>
                obis           : 8181c78205ff (129-129:199.130.5*255)
                status         : None
                val_time       : None
                unit           : None
                scaler         : None
                value          : XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
                value_signature: None
                -> (Öffentlicher Schlüssel)
        list_signature  : None
        act_gateway_time: None
    crc16         : 22117
SmlMessage
    transaction_id: 17c77d6d
    group_no      : 0
    abort_on_error: 0
    message_body <SmlCloseResponse>
        global_signature: None
    crc16         : 56696

Different CRC functions

Some meters e.g. the Holley DTZ541 via RS485 require a different crc function. You can set the crc function when creating the StreamReader.

Example:

from smllib import SmlStreamReader

stream = SmlStreamReader(crc='kermit')  # <-- use kermit for Holley DTZ541
stream.add(b'BytesFromSerialPort')
sml_frame = stream.get_frame()