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Hot!SIEMENS BSB and LPB protocol

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2012/12/02 02:31:03 (permalink)

SIEMENS BSB and LPB protocol

My home-control project is based on a workstation for every room, connected with TCP/IP (PIC32 + ENC).
Now I have a new device to interface: Siemens HVAC controller RVS41.813, that uses the protocol BSB and/or the LPB.
Both use two polarized wires.
Does anyone know these protocols? (It seems to be a top secret of Siemens-Swiss-Boys)
I'm sorry if I'm not in the right forum, but I've exhausted all Google's searches.

PDF: CE1N2032E CE1N2030E

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    Re:SIEMENS BSB and LPB protocol 2012/12/02 04:34:09 (permalink)
    +3 (2)
    Have you asked Siemens?  They might require something like your registering your details on their website before they will allow you to download the protocol spec.  Companies can be a bit funny about such things, they often like to know who's using their tech and for what purpose.

    non illegitimi carborundorum
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    Re:SIEMENS BSB and LPB protocol 2012/12/17 09:05:29 (permalink)
    I have already asked Siemens, but with no reply, they sell some interfaces as OZW672, so I think they do not want to disclose information.
    The CE1N2032E manual lists the following information:
    Technical data

    Physical Layer to            Voltage level and character transmission are in compliance with NF C 46621.
    Data Link Layer to          Bus access procedure, telegram makeup, telegram transmission and data protection
    ISO/OSI                          are in compliance with NF C 46 622.
    Application Layer to        Conforming to specific Landis & Staefa standards.
    Open-circuit voltage of   15.5 V ±10 % (with no load)
    Signal level                      < 7 V: logic ‘1’
                                            > 9 V: logic ’0’
    Polarity                            Not interchangeable (+-)
    Cable                               Two-core, twisted
                                           Cable capacitance ≤100 pF / m at 800 Hz
                                                                          (greater values require a proportional reduction
                                                                          of the permissible total cable length, refer to
                                                                          “Engineering notes”)
                                            Cross-sectional area, resistance and length: refer to “Engineering notes”
    The best protection against interference is achieved with screened two-core cabl
    The best results are obtained with cables protected by a tight braid, followed by c
    protected by a foil. Vapour-plated screening is unsuited.
    Bus topology                   Line, tree, star, or their combinations
                                          Note: for lightning protection reasons, it is not advisable to use the ring topology
    Character                       NRZ coding, 8 data bit, odd parity, 1 stop bit
    Baud rate                        4,800 Baud
    Telegram length              Max. 32 characters
    Transmission capacity     Approx. 10 telegrams per second on average
    Bus access procedure     CSMA / CA (multiple access with collision avoidance)
    Address range                1..240, can be assigned to 15 groups / segments each with 16 devices
    Number of users             With the distributed bus power supply: max. 16
                                          With the central bus power supply: refer to “Engineering notes”
    What kind of protocol is it ?  RS485 ?
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    Re:SIEMENS BSB and LPB protocol 2012/12/17 09:31:40 (permalink)
    +2 (1)
    NF standards are the French EU ones. You need to track down NF C 46 221 and NF C 46 221.    Expect them to be behind a pay-wall somewhere, and you'd better be fluent in technical French.   They've already given you most of what you need to figure out the physical layer so you may be able to skip NF C 46 221 if this is a one-off.  I *suspect* it resembles RS232 only with an 8V positive offset.  However it may be opto-isolated.
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    Re:SIEMENS BSB and LPB protocol 2021/01/06 15:17:18 (permalink)
    +3 (3)
    This thread may be almost 10 years old, but it is among the first when you google "BSB Siemens", so I would like to share the information with you that we have successfully decoded not only the BSB (Boiler System Bus) protocol, but also the phsyically identical LPB (Local Process Bus) and PPS ("Punkt-zu-Punkt-Schnittstelle").
    Detailed information, including software to control your heater as well as interface schematics can be found here:
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