boswatch.decoder.pocsagDecoder.PocsagDecoder Class Reference

POCSAG decoder class. More...

Static Public Member Functions
def	decode (data)
	Decodes POCSAG.

Static Protected Member Functions
def	_getBitrateRicSubric (data)

Detailed Description

POCSAG decoder class.

This class decodes POCSAG data.
First step is to validate the data and _check if the format is correct.
In the last step a valid BOSWatch packet is created and returned

Member Function Documentation

decode()

def boswatch.decoder.pocsagDecoder.PocsagDecoder.decode (   data )

static

Decodes POCSAG.

    @param data: POCSAG for decoding
    @return BOSWatch POCSAG packet or None

    def decode(data):
        r"""!Decodes POCSAG
 
        @param data: POCSAG for decoding
        @return BOSWatch POCSAG packet or None"""
        bitrate, ric, subric = PocsagDecoder._getBitrateRicSubric(data)
 
        # If no valid SubRIC (Function 0–3) detected → abort
        if subric is None:
            logging.warning("Invalid POCSAG function (not 0–3)")
            return None
 
        if ric and len(ric) == 7:
            if "Alpha:" in data:
                message = data.split('Alpha:')[1].strip()
                message = re.sub(r'<\s*(?:NUL|EOT)\s*>?', '', message).strip()
            else:
                message = ""
            subricText = subric.replace("1", "a").replace("2", "b").replace("3", "c").replace("4", "d")
 
            logging.debug("found valid POCSAG")
 
            bwPacket = Packet()
            bwPacket.set("mode", "pocsag")
            bwPacket.set("bitrate", bitrate)
            bwPacket.set("ric", ric)
            bwPacket.set("subric", subric)
            bwPacket.set("subricText", subricText)
            bwPacket.set("message", message)
 
            return bwPacket
 
        logging.warning("no valid POCSAG")
        return None
 

_getBitrateRicSubric()

def boswatch.decoder.pocsagDecoder.PocsagDecoder._getBitrateRicSubric (   data )

staticprotected

Gets the Bitrate, Ric and Subric from data using robust regex parsing.

    def _getBitrateRicSubric(data):
        """Gets the Bitrate, Ric and Subric from data using robust regex parsing."""
        bitrate = "0"
        ric = None
        subric = None
 
        # determine bitrate
        if "POCSAG512:" in data:
            bitrate = "512"
        elif "POCSAG1200:" in data:
            bitrate = "1200"
        elif "POCSAG2400:" in data:
            bitrate = "2400"
 
        # extract RIC (address)
        m_ric = re.search(r'Address:\s*(\d{1,7})(?=\s|$)', data)
        if m_ric:
            ric = m_ric.group(1).zfill(7)
 
        # extract SubRIC (function)
        m_sub = re.search(r'Function:\s*([0-3])', data)
        if m_sub:
            subric = str(int(m_sub.group(1)) + 1)
 
        return bitrate, ric, subric