speedwiredecoder.py

"""
 *
 * by david-m-m 2019-Mar-17
 * by datenschuft 2020-Jan-04
 *
 *  this software is released under GNU General Public License, version 2.
 *  This program is free software;
 *  you can redistribute it and/or modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; version 2 of the License.
 *  This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 *  without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 *  See the GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License along with this program;
 *  if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */
"""

import binascii

# unit definitions with scaling
sma_units={
    "W":    10,
    "VA":    10,
    "VAr":    10,
    "kWh":   3600000,
    "kVAh":   3600000,
    "kVArh":   3600000,
    "A":    1000,
    "V":    1000,
    "°": 1000,
    "Hz": 1000,
}

# map of all defined SMA channels
# format: <channel_number>:(emparts_name>,<unit_actual>,<unit_total>)
sma_channels={
    # totals
    1:('pconsume','W','kWh'),
    2:('psupply','W','kWh'),
    3:('qconsume','VAr','kVArh'),
    4:('qsupply','VAr','kVArh'),    
    9:('sconsume','VA','kVAh'),
    10:('ssupply','VA','kVAh'),
    13:('cosphi','°'),
    14:('frequency','Hz'),
    # phase 1
    21:('p1consume','W','kWh'),
    22:('p1supply','W','kWh'),
    23:('q1consume','VAr','kVArh'),
    24:('q1supply','VAr','kVArh'),
    29:('s1consume','VA','kVAh'),
    30:('s1supply','VA','kVAh'),
    31:('i1','A'),
    32:('u1','V'),
    33:('cosphi1','°'),
    # phase 2
    41:('p2consume','W','kWh'),
    42:('p2supply','W','kWh'),
    43:('q2consume','VAr','kVArh'),
    44:('q2supply','VAr','kVArh'),
    49:('s2consume','VA','kVAh'),
    50:('s2supply','VA','kVAh'),
    51:('i2','A'),
    52:('u2','V'),
    53:('cosphi2','°'),
    # phase 3
    61:('p3consume','W','kWh'),
    62:('p3supply','W','kWh'),
    63:('q3consume','VAr','kVArh'),
    64:('q3supply','VAr','kVArh'),
    69:('s3consume','VA','kVAh'),
    70:('s3supply','VA','kVAh'),
    71:('i3','A'),
    72:('u3','V'),
    73:('cosphi3','°'),
    # common
    36864:('speedwire-version',''),
}

def decode_OBIS(obis):
  measurement=int.from_bytes(obis[0:2], byteorder='big' )
  raw_type=int.from_bytes(obis[2:3], byteorder='big')
  if raw_type==4:
    datatype='actual'
  elif raw_type==8:
    datatype='counter'
  elif raw_type==0 and measurement==36864:
    datatype='version'
  else:
    datatype='unknown'
    print('unknown datatype: measurement {} datatype {} raw_type {}'.format(measurement,datatype,raw_type))
  return (measurement,datatype)

def decode_speedwire(datagram):
  emparts={}
  # process data only of SMA header is present
  if datagram[0:3]==b'SMA':
    # datagram length
    datalength=int.from_bytes(datagram[12:14],byteorder='big')+16
    #print('data lenght: {}'.format(datalength))
    if datalength != 54:
      # serial number
      emID=int.from_bytes(datagram[20:24],byteorder='big')
      #print('seral: {}'.format(emID))
      emparts['serial']=emID
      # timestamp
      timestamp=int.from_bytes(datagram[24:28],byteorder='big')
      #print('timestamp: {}'.format(timestamp))
      # decode OBIS data blocks
      # start with header
      position=28
      while position<datalength:
        # decode header
        #print('pos: {}'.format(position))
        (measurement,datatype)=decode_OBIS(datagram[position:position+4])
        #print('measurement {} datatype: {}'.format(measurement,datatype))
        # decode values
        # actual values
        if datatype=='actual':
          value=int.from_bytes( datagram[position+4:position+8], byteorder='big' )
          position+=8
          if measurement in sma_channels.keys():
            emparts[sma_channels[measurement][0]]=value/sma_units[sma_channels[measurement][1]]
            emparts[sma_channels[measurement][0]+'unit']=sma_channels[measurement][1]
        # counter values
        elif datatype=='counter':
          value=int.from_bytes( datagram[position+4:position+12], byteorder='big' )
          position+=12
          if measurement in sma_channels.keys():
            emparts[sma_channels[measurement][0]+'counter']=value/sma_units[sma_channels[measurement][2]]
            emparts[sma_channels[measurement][0]+'counterunit']=sma_channels[measurement][2]
        elif datatype=='version':
          value=datagram[position+4:position+8]
          if measurement in sma_channels.keys():
            bversion=(binascii.b2a_hex(value).decode("utf-8"))
            version=str(int(bversion[0:2],16))+"."+str(int(bversion[2:4],16))+"."+str(int(bversion[4:6],16))
            revision=str(chr(int(bversion[6:8])))
            #revision definitions
            if revision=="1":
                #S – Spezial Version
                version=version+".S"
            elif revision=="2":
                #A – Alpha (noch kein Feature Complete, Version für Verifizierung und Validierung)
                version=version+".A"
            elif revision=="3":
                #B – Beta (Feature Complete, Version für Verifizierung und Validierung)
                version=version+".B"
            elif revision=="4":
                #R – Release Candidate / Release (Version für Verifizierung, Validierung und Feldtest / öffentliche Version)
                version=version+".R"
            elif revision=="5":
                #E – Experimental Version (dient zur lokalen Verifizierung)
                version=version+".E"
            elif revision=="6":
                #N – Keine Revision
                version=version+".N"
            #adding versionnumber to compare versions
            version=version+"|"+str(bversion[0:2])+str(bversion[2:4])+str(bversion[4:6])
            emparts[sma_channels[measurement][0]]=version
          position+=8
        else:
          position+=8
  return emparts