BS EN 50090-5-3:2016 BSI Standards Publication Home and Building Electronic Systems (HBES) Part 5-3: Media and media dependent layers — Radio Frequency for HBES Class BS EN 50090-5-3:2016 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 50090-5-3:2016 It supersedes BS EN 50090-5-3:2006 which is withdrawn The UK participation in its preparation was entrusted to Technical Committee IST/6/-/12, Home Electronic Systems A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © The British Standards Institution 2016 Published by BSI Standards Limited 2016 ISBN 978 580 91842 ICS 97.120 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 February 2016 Amendments/corrigenda issued since publication Date Text affected BS EN 50090-5-3:2016 EUROPEAN STANDARD EN 50090-5-3 NORME EUROPÉENNE EUROPÄISCHE NORM January 2016 ICS 97.120 Supersedes EN 50090-5-3:2006 English Version Home and Building Electronic Systems (HBES) - Part 5-3: Media and media dependent layers - Radio Frequency for HBES Class Systèmes électroniques pour les foyers domestiques et les bâtiments (HBES) - Partie 5-3: Médias et couches dépendantes des médias - Radio Fréquence pour HBES Classe Elektrische Systemtechnik für Heim und Gebäude (ESHG) Teil 5-3: Medien und medienabhängige Schichten Signalübertragung über Funk für ESHG Klasse This European Standard was approved by CENELEC on 2015-11-02 CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CENELEC member This European Standard exists in three official versions (English, French, German) A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels © 2016 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members Ref No EN 50090-5-3:2016 E BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) Contents Page European foreword Introduction Scope Normative references 3.1 3.2 Terms, definitions and abbreviations Terms and definitions Abbreviations General 5.1 5.1.1 5.1.2 5.1.3 5.2 5.2.1 5.2.2 5.2.3 HBES RF Physical Layer Physical Layer for HBES RF Ready Signalling for HBES RF Ready Telegram structure for RF Ready Medium access RF Ready Physical Layer for HBES RF Multi General requirements (HBES RF Multi) Physical Layer type RF Multi 11 Telegram structure for HBES RF Multi systems 13 6.1 6.1.1 6.1.2 6.1.3 6.1.4 6.1.5 6.2 6.2.1 6.2.2 6.3 6.3.1 6.3.2 6.3.3 6.3.4 6.3.5 6.3.6 6.3.7 6.3.8 6.3.9 6.4 HBES RF Data Link Layer 13 HBES RF Data Link Layer for all HBES RF devices 13 Differences to existing (bidirectional) HBES EN 50090 protocol 13 Data Link Layer Frame 15 Use of the HBES Ctrl Field 18 Data Link Layer protocol 18 Data Link Layer services 19 HBES RF Data Link Layer for HBES RF Ready 21 Data Link Layer protocol 21 The Layer-2 of an RF Retransmitter 21 HBES RF Data Link Layer specific to HBES RF Multi systems 22 Medium access RF Multi 22 Frame format 24 RF Multi-channel usage 24 Fast Acknowledgment 30 Data Link Layer protocol 35 Runtime with an RF Repeater and Fast Ack requested 38 InterFrame delays for RF Repeaters 38 Repetition counter 39 Media Coupler 39 Semi-directional devices and bidirectional mode 39 7.1 7.2 7.3 Compatibility between HBES Ready and HBES RF Multi 40 Communication between HBES RF 1.1 and HBES RF1 Multi devices 40 Communication between HBES RF Ready and HBES RF Multi devices 41 Communication between HBES RF Multi and HBES RF Multi devices 41 Bibliography 42 BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) European foreword This document (EN 50090-5-3:2016) has been prepared by CLC/TC 205 "Home and Building Electronic Systems (HBES)" The following dates are fixed: • • latest date by which this document has to be implemented at national level by publication of an identical national standard or by endorsement latest date by which the national standards conflicting with this document have to be withdrawn (dop) 2016-11-02 (dow) 2018-11-02 This document supersedes EN 50090-5-3:2006 EN 50090-5-3:2016 EN 50090-5-3:2006: - includes the following significant technical changes with respect to the difference between this version and the previous version of Part 5-3 is that the previous version contained only a description of the HBES RF Ready solution, where the current version was extended with the upward compatible HBES RF Multi solution Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) Introduction CENELEC takes no position concerning the evidence, validity and scope of patent rights KNX Association as Cooperating Partner to CENELEC confirms that to the extent that the standard contains patents and like rights, the KNX Association's members are willing to negotiate licenses thereof with applicants throughout the world on fair, reasonable and non-discriminatory terms and conditions KNX Association De Kleetlaan 5, Bus 11 B-1831 Brussels-Diegem Tel: +32 (0)2 775 86 44 Mob: +32 (0) 476 21 56 58 Fax: +32 (0)2 675 50 28 e-mail: info@knx.org www.knx.org Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights other than those identified above CENELEC shall not be held responsible for identifying any or all such patent rights CEN and CENELEC maintain online lists of patents relevant to their standards Users are encouraged to consult the lists for the most up to date information concerning patents (ftp://ftp.cencenelec.eu/EN/IPR/Patents/IPRdeclaration.pdf) BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) Scope This European Standard defines the mandatory and optional requirements for the medium specific Physical and Data Link Layer of HBES Radio Frequency Data Link Layer interfaces and general definitions that are medium independent are given in EN 50090-4-1 This European standard defines the requirements for HBES RF Ready and HBES RF Multi devices HBES RF Ready is a single RF channel system HBES RF Multi is an RF multichannel evolution of HBES RF Ready system with additional RF channels for fast reaction time products and RF channels for slow reaction time products HBES RF Multi, specified below provides the following features: - more reliability in Frame transmissions in presence of interferers more efficiency when more HBES RF products are installed at the same location mixing of permanent and non-permanent receiving products mixing of fast and slow reaction time devices Listen Before Talk Fast RF channels are mainly intended to be used with human controlled applications like for example lights, shutters… Slow RF channels are mainly intended to be used with non-permanent receivers for automatic applications like sensors (smoke, temperature, wind, etc.), heating control, etc Compatibility issues with products in compliance with the former HBES RF specification (HBES RF 1.1) and the new versions are considered in Clause at the end of this document Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies EN 50090-1:2011, Home and Building Electronic Systems (HBES) — Part 1: Standardization structure EN 50090-4-1, Home and Building Electronic Systems (HBES) — Part 4-1: Media independent layers — Application layer for HBES Class EN 50090-4-2, Home and Building Electronic Systems (HBES) — Part 4-2: Media independent layers — Transport layer, network layer and general parts of data link layer for HBES Class ETSI EN 300 220 (all parts), Electromagnetic compatibility and Radio spectrum Matters (ERM); Short Range Devices (SRD); Radio equipment to be used in the 25 MHz to 000 MHz frequency range with power levels ranging up to 500 mW 3.1 Terms, definitions and abbreviations Terms and definitions For the purposes of this document, the terms and definitions given in EN 50090-1:2011 and the following apply 3.1.1 RF channel hopping action to change the RF channel during or after transmitting a frame BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) 3.1.2 budget link budget link of a device is the difference expressed in dB between the max radiated power and the radiated sensitivity The higher the budget link, the better the radio range is 3.2 Abbreviations AFA Adaptive Frequency Agility BER Bit Error Rate D.C Duty Cycle DLL Data Link Layer EOA End of Ack ERP Effective Radiated Power F1 F1 RF channel with a preamble of 15 ms in the transmitted Frame F1r F1 RF channel with a preamble of 4,8 ms in the transmitted Frame F1sh F1 RF channel with a preamble of 1ms in the transmitted Frame FSK Frequency Shift Keying Fx One of F1, F2 or F3 RF channels GFSK Gaussian Frequency Shift Keying LBT Listen Before Talk NPRM Non-Permanent Reception Mode PhL Physical Layer PRM Permanent Reception Mode Rx Receiver RSSI Received Signal Strength Indication SN HBES Serial Number Sx One of S1 or S2 RF channels TRx Transceiver Tx Transmitter General As described in the scope, this European standard defines the RF Physical Layer requirements for: - HBES RF Ready; - HBES RF Multi BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) For HBES certification in Europe, the products shall be in compliance with at least one of the following clauses Table — Guide for compliance System Physical Layer Data Link Layer HBES RF Ready 5.1 6.1 and 6.2 HBES RF Multi 5.2 6.1 and 6.3 HBES RF Physical Layer 5.1 5.1.1 Physical Layer for HBES RF Ready Signalling for HBES RF Ready Table — General requirements for Physical Layer Type HBES RF Ready Characteristic Value or applicable standard Tx centre frequency fc = 868,300 MHz Bandwidth 600 kHz Max Tx frequency tolerance ± 25 ppm Tx duty cycle max 1% Tx modulation type FSK FSK deviation fDEV = ± 48 kHz to ± 80 kHz typically 60 kHz Tx chip rate 32 768 chips per second Maximum Tx chip rate tolerance ± 1,5 % a Maximum Tx jitter per transition ± µs Tx ERP Typical : dBm Min : -3 dBm Max: +14dBm Rx blocking performance according to ETSI EN 300 220-1, category receivers Rx centre frequency fc = 868,300 MHz Rx frequency tolerance ± 25 ppm HBES Tx to HBES Rx a, b ± 60 ppm Metering Tx to HBES Rx Minimal Rx chip rate tolerance ±2,0 % Rx radiated sensitivity typical: minimal: Minimal operating temperature range 0°C to 45°C b a, b b b -95 dBm b -80 dBm c a This frequency tolerance includes tolerances due to temperature variations within the operating temperature range and tolerances due to crystal aging b At Bit Error Rate (BER) 10 in optimum antenna direction c HBES Physical Layer parameters shall be met for the entire product temperature range declared by the manufacturer (e.g : -10°C to 70°C for outdoor usage) -4 A link budget of 100 dB is recommended BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) 5.1.2 Telegram structure for RF Ready Table — HBES Ready systems Telegrams definition Characteristics Value Notes Data encoding Manchester Preheader consists of Manchester Sync word Preamble 79x chip sequence "01" learning sequence for Rx, number of preamble chips is sent by Tx not checked by Rx (~4.8 ms) Manchester violation chip sequence "000111" Sync word chip sequence useful for synchronization on chip rate "011010010110" Postamble chips to chips software reasons, mandatory for all Tx, number of postamble not checked by Rx Capture effect optional Preheader allows it; Rx may use it 5.1.3 5.1.3.1 chip "0" means fLO (= fC - fDEV) chip "1" means fHI (= fC + fDEV) bit "0" is coded as fHI to fLO transition, chip sequence "10" bit "1" is coded as fLO to fHI transition, chip sequence "01" Preamble, see below violation, necessary for capture effect Medium access RF Ready Definition and use Medium access control shall serve for prevention of collisions on the RF medium For two reasons medium access cannot be completely controlled on RF 1) Unidirectional senders access the medium at non-predictable times 2) Non HBES RF devices access the medium at non-predictable times Bidirectional devices shall be able to sense whether the medium is free before they transmit The interFrame time shall be the time interval during which a bidirectional device shall wait for a free medium (regardless of whether it is addressed by a preceding Frame or not) If no preamble is detected during this interFrame time the device may start sending If a Frame is received while the Physical Layer gets a request to send, the interFrame time shall start after the Frame reception is completed, this is after the last CRC is received The same shall apply for sending: if the Physical Layer gets a send request while it is sending, the interFrame time shall start when the last CRC is transmitted NOTE RF supports no collision avoidance; therefore the transmission priorities are not coded in the Frame BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) Table 13 specifies the Telegrams that shall be sent by a sensor according to the reception capabilities of the actuators associated to the sensor Table 13 — Transmission matrix Transmitter Bidir sensor 6.3.4 6.3.4.1 Telegrams sent Receiver One Frame in one FastRF channel Only fast devices One Frame in one FastRF channel + One Frame in one SlowRF channel Fast and slow devices One Frame in one SlowRF channel Only slow devices Fast Acknowledgment Basic requirements The main risk in such an environment is to have transmissions in different RF channels at the same time As it is not possible to avoid this, the system shall detect those situations and retry to reach the destination, therefore an acknowledgement is necessary A Fast Ack is allowed by EN300220, provided that it is sent by the destination within the first ms after the end of the received Frame The Fast Ack is optional and may be decided by the relevant manufacturer A transmitter shall be aware of the Fast Ack capability during the configuration phase Therefore, in the case of a multicast communication with a Fast Ack requested and both type of devices answering, the transmitter shall only consider expected Ack Devices without the Ack capability shall be considered by default as having received the transmission 6.3.4.2 Principle In order to indicate to the destination that a Fast Ack is expected, the HBES field bit shall be set to Value of Bit HBES CTRL field Meaning Fast Ack requested Fast Ack not requested Moreover, to have enough time to check the content of the received Frame a postamble extension to ms is necessary BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) 6.3.4.3 Postamble with End of Ack This postamble shall occupy the medium until the destinations products are able to answer A synchro word and the number of Ack expected are necessary for installations with Repeaters The format of the Postamble shall be as specified in Figure 12 Start Synchro Word Number expected of Ack Number of expected Ack CRC End Figure 12 — Postamble with End of Ack message content • Start Description: 123x chip sequence “01” • Synchro word Description: Manchester violation “000111” chip sequence followed by the sequence “011011011011” • Number of Fast Ack expected (1B) Description: Number of Ack expected by the sender excluding Repeaters Encoding: • Redundant number of Fast Ack expected (1B) Description: Number of Ack expected by the sender excluding Repeaters • CRC (1B) Description: The last bits from CRC according to IEC870-5-1 16 13 12 11 10 (2 +2 +2 +2 +2 +2 +2 +2 +2 +2 ) CRC is calculated using the previous octets (number of Fast Ack) • End Description: Encoding: chip sequence “01” Postamble with EOA message total length is 20 octets, that is 9,76 ms with 32 786 kchips The "number of Fast Ack expected" value shall be within the range from to 64 to avoid increasing the latency for the application In case of transmission error in the number of Ack expected, it is advised to keep the smallest value of the two octets ms ms 5ms Main Frame EOA T1=T0+732µs Wait Wake -up ( postamble) Ack R1 T0 T1= ms ms Ack R2 ms Ack Rn 11 ms (1+5[n-1 ]) ms (1+5n ) ms Figure 13 — General Ack insertion 10 ms after the end of the main Frame (i.e ms after the end of the postamble), the first receiver shall send its acknowledge message After that, the second receiver shall send its message and so on until the last concerned receiver Every concerned receiver shall have its own time-slot to send its message All receivers shall be synchronized on the same starting point at the end of the postamble synchro word The time windows shall be ms The Receiver’s Ack order (for receivers) as well as receivers list (for transmitter) shall be defined by configuration The Ack transmission shall be sent between 0,1 ms and 0,3 ms after the beginning of the time-slot This requires a maximum tolerance on the microcontroller oscillator of ± 0,05 % BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) For group communication, the transmitter shall be configured with the list of the destinations devices and their Ack slot number in the configuration; therefore, the device knows how many Acks are expected The transmitter of the initial Frame shall check the received acknowledges and handle the error if any Attention shall be made to links that may be deleted thus creating "empty holes" in the Ack list The same acknowledgment mechanism applies also to Slow RF channels but with a lower data rate All timings are changed accordingly The limit of 64 devices by group for Fast Ack can be overridden for specific installations 6.3.4.4 Ack Frame format The Ack Frame shall always be sent on the same RF channel as the Frame that it acknowledges The format of the Ack Frame shall be as specified in Figure 14 Short Preamble Synchro HBES Ctrl Info CRC 18 chips chips octet octet octets Figure 14 — Ack Frame format • Short Preamble Description: Short preamble for Frame transmitter synchronization Encoding: 18 sequence of “01” chip • Synchro Description: Encoding: The use shall be the same as in the main HBES Frame chip sequence "011010010110" • HBES Ctrl Description: HBES Control (same use as main HBES Frame) Encoding: octet • Info Encoding: 00h (Default value if not used Otherwise optional values below shall be used) rrr rrrr: Value: 000 x rrrr : RSSI value Reception level is calculated by [-113 dBm + × RSSI Value (1 to 31)] If RSSI value = 31 the reception level is ≥ -20 dBm 01 r rrrr : Temperature (internal of the device, board temp) 10 r rrrr : Reserved for future use 11 r rrrr : Reserved for future use 1rrr rrrr: Technical alarm/ error: 1000 0rrr : Environmental issue 1000 0001 : Frozen 1000 0010 : Overheat 1000 0rrr : All values except the above are reserved 1000 1000 : Lamp failure (defective output) 1000 1001 : Application busy 1rrr rrrr : All values except above are reserved FFh value is reserved for Repeaters Reserved bits (r) are reserved for the HBES system and shall be set to zero BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) • CRC Description: 16 13 12 11 10 CRC according to IEC870-5-1 (2 +2 +2 +2 +2 +2 +2 +2 +2 +2 ) The Fast Ack Frame shall have a total length of octets; that is 3,41 ms at 32,786 kchips The same acknowledgment mechanism shall apply also to Slow RF channels but with a lower data rate All timings shall be changed accordingly 6.3.4.5 Time-slot filling In case of one or several acknowledges are missing, time-slot(s) left free shall be filled in order not to lose the RF channel Any free time slot shall be filled by the transmitter The fill transmission shall be to 10 times a sequence of “0011” chips corresponding roughly to ms R2' s time slot Main Frame Wait Wake-up ( postamble) EOA T1=T0+732µs T0 T1 = ms ms Ack R3 Fill Ack R1 ms ms ms 10 ms 11 ms + 5(n-1 ) ms Ack Rn + n ms Frame transmitter listens and gets nothing after 2ms Frame transmitter switches RX -> TX Frame transmitter switches TX -> RX Figure 15 — Time-slot filling (R2 KO) In this way, the maximum gap shall be ms (two consecutive missing Ack Frames) The same acknowledgment mechanism shall apply also to Slow RF channels but with a lower data rate All timings shall be changed accordingly 6.3.4.6 6.3.4.6.1 Runtime flowcharts Transmitter side Transmit frame Ack missing Handle error (Transmit frame again) Listen to Ack All ack received or too many retries Idle Figure 16 — Acknowledge algorithm, transmitter side BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) Ack(s) missing Is there a repeater ? Yes Yes Timeout No Repeat frame on another channel Ack(s) missing? No Extended time, wait for service messages Yes Are there still ack(s) missing Frame repeated on all channels? Yes No End No Figure 17—Acknowledge algorithm, handle error If a Frame is transmitted for which Fast Acks are expected then the sender shall set a timeout to check if a Repeater is present in the installation or not To determine if there is a repeater, the device shall switch to reception mode to wait for the Echo frame (i.e repeated frame) The timeout for the reception of the echo Frame is defined as follows: Repeater interFrame (5 ms) + max random Repeater (10 ms) + sufficient time to process the repeated Frame (60 ms) = 75 ms Fast RF channel If a Repeater is detected because of the reception of the echo Frame, the device shall set another timeout for the reception of the Ack Rep Frames This timeout shall be dependant of the length Frame and the number of expected Fast Acks The timeout shall be the following 000 ms if less than 32 Acks are expected 000 ms more than 32 Fast Acks are expected Slow RF channel If a Repeater is detected by the reception of the echo Frame, the sender shall set another timeout for the reception of the Ack Rep Frames This timeout shall be dependant of the length Frame and the number of expected Fast Acks The timeout is the following: 000 ms if less than 32 Fast Acks are expected 000 ms if more than 32 Fast Acks are expected Of course these timeouts are not used if all the expected Fast Acks have been received In the case of group communication, if one or several Ack messages are missing, the device shall send the Frame again but on the next RF channel The Ack mechanism shall stop after successive immediate retries on the two next RF channels after the Call Channel, and the Call Channel A typical sequence would be F1, and retries on F2, F3 and F1 The same applies for Slow RF channels with S1 and S2 BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) 6.3.4.6.2 Receiver side Receive frame Wait for time slot Send Ack Idle Figure 18 — Acknowledge algorithm, receiver side 6.3.5 Data Link Layer protocol 6.3.5.1 RF Repetition counter for end devices The RF Repetition counter shall be set to for end devices 6.3.5.2 6.3.5.2.1 The Layer-2 of an RF Retransmitter General requirements Any RF Retransmitter shall be either one of the following two types: a fast Repeater or a slow Repeater A Repeater shall repeat once any Telegrams received coming from the device it is configured with For HBES RF Multi, filtering is the rule Fast Repeaters shall be mains powered but slow Repeaters may be battery driven Operating on fast HBES RF Multi Telegrams, it shall receive and repeat any fast Frame It shall use the frequencies F1, F2 and F3 Operating on slow HBES RF Multi Telegrams, it shall receive and repeat any slow Frame It shall use the frequencies S1 and S2 The HBES RF Repeater can be generic device The selection of fast or slow Repeater function is done by HMI A Repeater shall repeat frames whatever the LFN value is but shall not repeat a frame that is already in the history list There is only one entry per HBES Serial Number; the LFN is overwritten On fast RF channels, the Repeater shall adapt the preamble length according to the product it is linked with This is, the preamble length shall be 15 ms or 4,8 ms This implies a scanning sequence according to Figure for a fast Repeater or Key S for scan, Hop for Hopping, Rx for receiving mode ms for hopping, ms for listening or scanning or less Figure for fast and slow Repeater or Figure 10 for a slow Repeater A fast and slow Repeater may lose or delay the repetition of fast Frames in case a simultaneous slow Frame occurs, therefore this implementation is not recommended The interFrame time of ms between a reception and the following transmission apply to Repeaters BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) 6.3.5.2.2 Working principle Figure 19 — General Repeater algorithm By default, the system is scanning the RF channels At regular intervals (depending on the kind of Repeater), the Repeater shall scan its RF channels to see if a HBES Frame is being transmitted If not, it shall inspect the Frame queue In case of a non-empty queue, the first Frame in the queue shall be transmitted Else it shall get back to its scanning idle state If a Frame is detected, the Repeater shall receive the Frame It shall then check the Frame to determine if the Frame is a correct HBES Frame It can also check if it has recently sent the same Frame to avoid any distortion or echo effect If the Frame is considered as bad, the Repeater shall get back to its scanning idle state If the Frame is correct then the Repeater shall queue that Frame The Repeater shall then get back to its scanning idle state, waiting for the next Frame 6.3.5.2.3 Fast Repeaters Fast Repeaters shall have two working modes, HBES RF Ready or HBES RF Multi For the HBES RF Ready, refer to the relevant clauses In this mode, all the Telegrams to be repeated shall be located on the same frequency As the preamble received may be only ms-long, the Repeater shall listen to the RF channel continuously and the queued Telegrams can be immediately transmitted Repeat queued frame Frame repeated Listen No Frame detected and queue not empty Waiting for a F1sh frame Acquire noise level Frame detected Queue frame Good frame Bad frame Check frame Receive frame Frame received Figure 20 — HBES RF Ready algorithm In the HBES RF Multi mode, the Telegrams to be repeated can be located on different frequencies (F1, F2, F3) The preamble of each Frame shall be 15 ms long; this allows the Repeater to be in complete low power mode most of the time BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) Channel OK Transmit frame Listen before talk Frame queue not empty Try to use the same channel, change if it is too noisy Frame queue inspection Frame queue empty No frame detected Frame repeated Timer interrupt Idle Scan F1, F2 and F3 Frame queued Queue frame Frame detected Bad frame Good frame Frame received Check frame CRC, recent history End of preamble Receive frame Frame detected Wait for the end of the preamble Figure 21 — Fast HBES RF Multi Repeater algorithm The scan described above is a real scan amongst the RF channels not used (e.g F2 and F3 if the Frame is received on F1) It is mandatory to a scan on each RF channel prior to transmitting because of the hidden node problem, as it may result in HBES Frames at the same moment on different RF channels 6.3.5.2.4 Slow Repeaters With this Repeater, the Telegrams to be repeated can be located on different frequencies (S1, S2) The preamble of each Frame shall be 500 ms long; this allows the Repeater to be in complete low power mode most of the time Channel OK Transmit frame Listen before talk Try to use the same channel, change if it is too noisy Frame queue not empty Frame queue inspection Frame queue empty Frame repeated Timer interrupt Idle No frame detected Scan S1 and S2 Frame queued Queue frame Good frame Frame detected Bad frame Check frame CRC, recent history Frame received Receive frame End of preamble Wait Frame detected for the end of the preamble Figure 22 — Slow Repeaters algorithm The scan described above is a real scan amongst the RF channels not used (e.g S2 if the Frame is received on S1) It is mandatory to a scan on each RF channel prior to transmitting because of the hidden node problem as it may result in HBES Frames at the same moment on different RF channels BS EN 50090-5-3:2016 EN 50090-5-3:2016 (E) 6.3.6 Runtime with an RF Repeater and Fast Ack requested A RF Repeater shall be dynamically aware that a second RF Repeater is present thanks to the repeated Frame with the same HBES Serial Number (Echo Frame) To wait for the Echo Frame, the Repeater shall be kept in receive mode at least 75 ms after the End Of Ack In absence of an RF Repeater, the retry shall be sent as soon as possible on the next free RF channel Only Frames learnt by the Repeater shall be repeated After a retransmission, the RF Repeater shall wait for all the Fast Ack and an Acknowledge Repeater (Ack Rep) Frame shall be sent back to the sender The Ack Rep Frame shall be a copy of the initial Frame sent by the sensor except for the following C field Start RC 00h (Ack Frame defined in IEC 870-5) See 6.1.3 Repetition counter is set to Field of n octets (n = number of Fast Ack requested in the EOA) Data field • In case a Fast Ack is received, the octet contains the Info Octet of the Fast Ack • In case a Fast Ack is NOT received, the octet is filled by FFh value The length of the Frame shall be adapted to the number n of Ack requested in the EOA received The max number of expected Fast Ack expected shall be limited to 64 An Ack Rep Frame shall have high priority compared to other application Frames if the Repeater is embedded in a device with another function A repeater that receives a Ack Rep frame shall always repeat it provided that the repetition counter is not equal to 6.3.7 InterFrame delays for RF Repeaters To be able to work efficiently, the repeated and Ack Rep Frames shall be sent before standard Frames Table 14 gives the interFrame and random times used for different frame types Table 14 — Transmission matrix Type of frame InterFrame time [Tint] Random time [Trd] Total medium access time [Tma] REPEATED Multi fast frame ms ms ≤ Trd