EN 50090-5-2:2004

SLOVENSKI STANDARD
01-september-2005
1DGRPHãþD
SIST CLC/R 205-009:1998
Stanovanjski in stavbni elektronski sistemi (HBES) - 5-2. del: Mediji in nivoji,
odvisni od medijev - Omrežja, ki temeljijo na HBES razreda 1, zviti par
Home and Building Electronic Systems (HBES) - Part 5-2: Media and media dependent
layers - Network based on HBES Class 1, Twisted Pair
Elektrische Systemtechnik für Heim und Gebäude (ESHG) - Teil 5-2: Medien und
medienabhängige Schichten - Netzwerk basierend auf ESHG Klasse 1, Twisted Pair
Systèmes électroniques pour les foyers domestiques et les bâtiments (HBES) - Partie 5-
2: Medias et couches dépendantes des medias - Réseau basé sur HBES Classe 1, Paire
Torsadée
Ta slovenski standard je istoveten z: EN 50090-5-2:2004
ICS:
97.120 Avtomatske krmilne naprave Automatic controls for
za dom household use
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN 50090-5-2
NORME EUROPÉENNE
EUROPÄISCHE NORM February 2004

ICS 97.120 Supersedes R205-009:1996

English version
Home and Building Electronic Systems (HBES)
Part 5-2: Media and media dependent layers -
Network based on HBES Class 1, Twisted Pair

Systèmes électroniques pour les foyers Elektrische Systemtechnik für Heim
domestiques et les bâtiments (HBES) und Gebäude (ESHG)
Partie 5-2: Medias et couches Teil 5-2: Medien und medienabhängige
dépendantes des medias - Schichten -
Réseau basé sur HBES Classe 1, Netzwerk basierend auf ESHG Klasse 1,
Paire Torsadée Twisted Pair
This European Standard was approved by CENELEC on 2003-12-02. 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 Central Secretariat or to any CENELEC member.

This European Standard exists in one official version (English). A version in any other language made by
translation under the responsibility of a CENELEC member into its own language and notified to the Central
Secretariat has the same status as the official version.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden,
Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© 2004 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 50090-5-2:2004 E
Contents
Foreword .5
Introduction.6
1 Scope.6
2 Normative references.6
3 Terms, definitions and abbreviations .7
3.1 Terms and definitions.7
3.2 Abbreviations.9
4 Requirements for HBES Class 1, Twisted Pair Type 0 (TP0) .10
4.1 Datagram service.10
4.2 Medium definition.14
4.3 Power feeding service .16
4.4 Data link layer type Twisted Pair Type 0.25
4.5 Full Twisted Pair Type 0 frame structure .35
5 Requirements for HBES Class 1, Twisted Pair Type 1 (TP1-64 & TP1-256) .36
5.1 Physical layer requirements – Overview .36
5.2 Requirements for analogue bus signals .38
5.3 Medium attachment unit (MAU) .43
5.4 Twisted Pair Type 1 bus cable.50
5.5 Topology.53
5.6 Services of the physical layer type Twisted Pair Type 1 .56
5.7 Behaviour of the physical layer type Twisted Pair Type 1 entity.58
5.8 Data link layer type Twisted Pair Type 1.58
Figure 1 – NRZ line code . 11
Figure 2 – Character format .11
Figure 3 – Transmitter rising and falling edges.12
Figure 4 – Repeater maximum transition time .15
Figure 5 – TP0 power supply gauge.18
Figure 6 – Power supply dynamic internal resistor measuring test set-up.18
Figure 7 – Falling edge and over-current measurements.19
Figure 8 – TP0 Network with distributed power supply .20
Figure 9 – Voltage / Current gauge of one node.21
Figure 10 – Voltage / Current gauge of entire distributed power supply
with 6 to 8 supplying nodes.24
Figure 11 – Common part of frame structure.26
Figure 12 – Control Field .26
Figure 13 – CTRLE Field .27
Figure 14 – Format1s, L_Data_Standard Frame Format
with standard field-name abbreviations .27
Figure 15 – Format 1e, L_Data_Extended Frame Format
with standard fieldname abbreviations .28
Figure 16 – EFF field .29

– 3 – EN 50090-5-2:2004
Figure 17 – Format 2, Short Acknowledgement frame format .30
Figure 18 – Transmission definition .35
Figure 19 – Format 1s, Full L_Data_Standard Request frame format .35
Figure 20 – Format 1e, Full L_Data_Extended Request frame format .36
Figure 21 – Logical structure of physical layer type TP1 .38
Figure 22 – Octet mapped to a serial character.38
Figure 23 – “1”-Bit frame.39
Figure 24 – “0”-Bit frame.40
Figure 25 – Delayed logical “0” .41
Figure 26 – Overlapping of two logical “0” (example) .42
Figure 27 – Method of transmitting.45
Figure 28 – Example of transmitter characteristics.46
Figure 29 – Example of a diagram of a TP1-64 transmitter.46
Figure 30 – Example of a diagram of a TP1-256 transmitter (I 0,4 A).47
limit
Figure 31 – Relation between framed data and asynchronous signal .48
Figure 32 – Relation between digital signal and serial bit stream .49
Figure 33 – Example of a Light Dimmer .50
Figure 34 – Physical Segments.53
Figure 35 – Physical segments combined to a line .54
Figure 36 – Lines combined to a zone.54
Figure 37 – Network topology .55
Figure 38 – Control Field .59
Figure 39 – Frame Fields with Standard Fieldname Abbreviations .59
Figure 40 – Format 1s, L_Data_Standard Frame Format.60
Figure 41 – Check octet.60
Figure 42 – Frame Fields with Standard Fieldname Abbreviations .61
Figure 43 – Format 1e, L_Data_Extended Frame Format .61
Figure 44 – Extended Control Field.62
Figure 45 – Format 3 - L_Poll_Data request frame format.62
Figure 46 – L_Poll_Data response frame format .63
Figure 47 – Format 2 - Short Acknowledgement frame format .64
Figure 48 – Character timing.64
Figure 49 – Priority operation.66
Figure 50 – Guarantee of access fairness .67
Figure 51 – State machine of data link layer .72
Table 1 – Electrical data encoding . 11
Table 2 – Transceiver characteristics – Sending part .12
Table 3 – Transceiver characteristics – Receiving part .13
Table 4 – Mandatory and optional requirements for physical layer services .13
Table 5 – Ph-Result parameter .14
Table 6 – Requirements for the TP0 line .15
Table 7 – General hardware requirements .16

Table 8 – Current consumption requirements.17
Table 9 – Power supply voltage .17
Table 10 – Requirements for one supplying DPS device .21
Table 11 – Requirements for entire DPS .23
Table 12 – Possible cable lengths depending on number of DPS devices connected
(for a typical cable) .24
Table 13 – Priority of frames – IFT.32
Table 14 – Requirements for Acknowledgement wait time, frame re-transmission .34
Table 15 – Requirements for full wait time, frame re-transmission.34
Table 16 – System parameters of physical layer Type TP1-64 and TP1-256 .37
Table 17 – Analogue and digital signal of a logical “1” .39
Table 18 – Analogue and digital signal of logical “0” .41
Table 19 – Limits within a character.42
Table 20 – Unit currents for standard devices .44
Table 21 – Dynamic requirements of a TP1-64 transmitter .45
Table 22 – Dynamic requirements of a TP1-256 transmitter .46
Table 23 – Requirements for the receiver .47
Table 24 – Requirements for bit coding.48
Table 25 – Requirements for the bit decoding unit .49
Table 26 – Requirements for TP1 cable .51
Table 27 – Requirements for character coding .65
Table 28 – Requirements for character decoding .65
Table 29 – Priority sequence, in descending order of importance.66

– 5 – EN 50090-5-2:2004
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 205, Home and
Building Electronic Systems (HBES) with the help of CENELEC co-operation partner Konnex Association
(formerly EHBESA).
The text of the draft was submitted to the Unique Acceptance Procedure and was approved by CENELEC
as EN 50090-5-2 on 2003-12-02.
This European Standard supersedes R205-009:1996.
CENELEC takes no position concerning the evidence, validity and scope of patent rights.
Konnex Association as Cooperating Partner to CENELEC confirms that to the extent that the standard
contains patents and like rights, the Konnex Association's members are willing to negotiate licenses
thereof with applicants throughout the world on fair, reasonable and non-discriminatory terms and
conditions.
Konnex Association Tel.:  + 32 2 775 85 90
Neerveldstraat, 105 Fax.: + 32 2 675 50 28
Twin House e-mail: info@konnex.org
B - 1200 Brussels www.konnex.org
Attention is drawn to the possibility that some of the elements of this standard 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.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2004-12-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2006-12-01
EN 50090-5-2 is part of the EN 50090 series of European Standards, which will comprise the following
parts:
Part 1: Standardisation structure
Part 2: System overview
Part 3: Aspects of application
Part 4: Media independent layers
Part 5: Media and media dependent layers
Part 6: Interfaces
Part 7: System management
Part 8: Conformity assessment of products
Part 9: Installation requirements

Introduction
According to OSI Physical Layers consist of the medium, the cable, the connectors, the transmission
technology etc. which refers to their hardware requirements. In this European Standard however, the
status of the Physical Layer as a “communication medium” is emphasized.
1 Scope
This European Standard defines the mandatory and optional requirements for the medium specific
physical and data link layer for HBES Class 1 Twisted Pair in its two variations called TP0 and TP1.
Data link layer interface and general definitions, which are media independent, are given in
EN 50090-4-2.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
1)
EN 50090-1 Home and Building Electronic Systems (HBES) –
Part 1: Standardisation structure
EN 50090-2-2 Home and Building Electronic Systems (HBES) –
Part 2-2: System overview – General technical requirements
EN 50090-3-2:2004 Home and Building Electronic Systems (HBES) –
Part 3-2: Aspects of application – User process for HBES Class 1
EN 50090-4-2:2004 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 1
Home and Building Electronic Systems (HBES) –
EN 50090-7-1:2004
Part 7-1: System Management – Management procedures
Home and Building Electronic Systems (HBES) –
EN 50090-9-1:2004
Part 9-1: Installation requirements – Generic cabling for HBES Class 1 Twisted
Pair
EN 50290 series Communication cables
Electromagnetic compatibility (EMC) –
EN 61000-4-5
Part 4-5: Testing and measurement techniques – Surge immunity test
(IEC 61000-4-5)
EN 61000-6-1 Electromagnetic compatibility (EMC) –
Part 6-1: Generic standards – Immunity for residential, commercial and light-
industrial environments (IEC 61000-6-1, mod.)
EN 61000-6-2 Electromagnetic compatibility (EMC) –
Part 6-2: Generic standards - Immunity for industrial environments
(IEC 61000-6-2, mod.)
HD 21.2 S2 Polyvinyl chloride insulated cables of rated voltages up to and including
450/750 V –
Part 2: Test methods (IEC 60227-2, mod.)
———————
1)
At draft stage.
– 7 – EN 50090-5-2:2004
HD 22.2 S2 Rubber insulated cables of rated voltages up to and including 450/750 V –
Part 2: Test methods (IEC 60245-2, mod.)
IEC 60189-2 Low-frequency cables and wires with PVC insulation and PVC sheath –
Part 2: Cables in pairs, triples, quads and quintuples for inside installations
IEC 60332-1 Tests on electric cables under fire conditions – Part 1: Test on a single vertical
insulated wire or cable
IEC 60754-2 Test on gases evolved during combustion of electric cables –
Part 2: Determination of degree of acidity of gases evolved during the combustion
of materials taken from electric cables by measuring pH and conductivity
3 Terms, definitions and abbreviations
3.1 Terms and definitions
For the purposes of this part the terms and definitions given in EN 50090-1 and the following apply.
3.1.1
HBES Class 1 Twisted Pair Type 0
the Twisted Pair medium Twisted Pair Type 0 (TP0) is a physical layer specification for data and power
transmission on a single twisted pair, allowing asynchronous character-oriented data transfer in a half
duplex bi-directional communication mode, using a specifically unbalanced/unsymmetrical base-band
signal coding with collision avoidance under SELV conditions
3.1.2
HBES Class 1 Twisted Pair Type 1
the Twisted Pair medium Twisted Pair Type 1 (TP1) is a physical layer specification for data and power
transmission on a single twisted pair, allowing asynchronous character-oriented data transfer in a half
duplex bi-directional communication mode, using a specifically balanced/symmetrical base-band signal
coding with collision avoidance under SELV conditions
3.1.3
distributed power supply
the bus is powered in a distributed way by a number of the devices connected to the line (compared to a
centralized power supply)
3.1.4
Logical Tag Extended HEE
usage of the L_Data_Extended frame dedicated to extended group addressing
3.1.5
Remote Powered Devices
remote Powered Bus Devices (RPD) do not extract their energy for the application circuit and the bus
controller from the bus but from another independent source of energy, e.g. mains. Owing to the reduced
DC power consumption of RPD, a bus line equipped with such devices requires less power from the
installed Power Supply Unit (PSU). The connection of bus-controller and application to the same electrical
potential reduces the effort of galvanic separation in RPD
3.1.6
TP0 C Factor
to simplify system engineering, the supply current of a TP0 device (both power supply and bus device) is
expressed by a factor "C”, defined as
Actual current
C =
Reference device supply current
The actual current can either be the one provided by a power supply or used by a device

3.1.7
TP0 Character
11 bit set including 8 data bits, 1 check bit (odd parity bit) and two synchronisation bits (start and stop
bits)
3.1.8
TP0 Distortion
percentage ratio of the deviation time between the instant a transition occurs and the ideal transition
instant, and the bit duration (~208 µs); the distortion is measured for each bit of a character, starting with
the start bit
3.1.9
TP0 Inter-Frame Time
time between the end of a frame (end of stop bit for the last character) and the beginning of the next
frame (beginning of the start bit of the first character)
3.1.10
TP0 Line Load
percentage ratio representing the proportion of actual character transmission during a specified
integration time interval
3.1.11
TP0 Odd parity bit
check bit whose value is such that there is an odd number of logic “0” within the data and parity fields
3.1.12
TP0 Repeater
connects a primary segment to a secondary segment
3.1.13
TP1 Backbone Couplers
15 backbone couplers can be used to couple up to 16 zones to a full sized TP1 network
3.1.14
TP1 Backbone Line
the main line of the inner zone is called backbone line
3.1.15
TP1 Bridge
four TP1-64 physical segments can be combined to a line by using bridges. To such a line 256 devices
can then be connected
3.1.16
TP1 Line
a TP1 line consists of a maximum of 256 devices, either directly connected in case of TP1-256 or
separated over 4 physical segments in case of TP1-64, each with 64 devices
3.1.17
TP1 Line Couplers
routers that combine lines to a zone are called line couplers
3.1.18
TP1 Logical Unit
converts the serial bit stream to octets and octets to the serial bit stream, which is a serial stream of
characters
– 9 – EN 50090-5-2:2004
3.1.19
TP1 Medium Access Unit
converts information signals to analogue signals and vice versa, typically extracts DC power from the
medium
3.1.20
TP1 Main line
the inner line of a zone is called main line
3.1.21
TP1 Physical Segment
a physical segment is the smallest entity in the TP1 topology. To a physical segment up to 64 devices can
be connected in case of TP1-64 and 256 in case of TP1-256
3.1.22
TP1 Polling Master
the device transmitting the Poll_Data frame is called the TP1 Polling master or Poll_Data master
3.1.23
TP1 Polling Slave
the device transmitting a Poll_Data character is called the TP1 polling slave or Poll_Data slave
3.1.24
TP1 Router
a router acknowledges frames on data link layer and transmits the received frame on the other side of the
router, provided the device associated with the destination address is located on the other side
3.1.25
TP1 Sub-line
the outer lines of a zone are called sublines or lines
3.1.26
TP1 Zone
16 TP1 lines can be connected to a zone by using 15 routers

3.2 Abbreviations
AC Alternating Current
ACK Acknowledge
APDU Application layer Protocol Data Unit
AT Address Type
CSMA/CA Carrier Sense, Multiple Access with Collision Avoidance
CKS Checksum
DA Destination Address
DC Direct Current
DL TP Data Link layer Type Twisted Pair
DPS Distributed Power Supply
CTRL Control Field
HBES Class 1 refers to simple control and command
HBES Class 2 refers to Class 1 plus simple voice and stable picture transmission
HBES Class 3 refers to Class 2 plus complex video transfers

IFT Inter-Frame-Time
LC Line Coupler
LN Length
LPDU Link layer Protocol Data Unit
LSDU Link layer Service Data Unit
LTE-HEE Logical Tag Extended HEE
MAU Medium Attachment Unit
NACK Negative Acknowledge
NPCI Network layer Protocol Control Information
NRZ Non-Return-to-Zero
OCP Over-Current Protection
PELV Protective Extra Low Voltage
PDU Protocol Data Unit
PSU Power Supply Unit
RPD Remote Powered Bus Devices
RUP Reverse Polarity Protection
SA Source Address
SDU Service Data Unit
SELV Safety Extra Low Voltage
TP Twisted Pair
TPDU Transport layer Protocol Data Unit
UART Universal Asynchronous Receiver Transmitter
up power up
4 Requirements for HBES Class 1, Twisted Pair Type 0 (TP0)
4.1 Datagram service
4.1.1 Transmission method
4.1.1.1 Description
The following subclauses specify the valid signals on the medium and the encoding and decoding rules
and the composition of characters and datagrams.
4.1.1.2 Modulation method
The open/closed circuit switching of the line shall be used as modulation technique.
4.1.1.3 Encoding rules
The line code shall be the Non-Return-to-Zero (NRZ) code using negative logic, as shown in Figure 1.
Logic “0” shall indicate the open-circuit state of the line (or idle state).
Logic “1” shall indicate closed-circuit state of the line for the duration of a bit time.

– 11 – EN 50090-5-2:2004
V on the line
Data: 1 1 0 10010
V “0”
open_circuit
“1”
V
closed_circuit
Figure 1 – NRZ line code
4.1.1.4 Bit rate
The line signal shall be transmitted at a rate of 4,8 kbit/s.
4.1.1.5 Electrical data encoding
Line open/closed-circuit modulation shall conform to the following values:
Table 1 – Electrical data encoding
Start Stop Logic Logic
“0” “1”
Receiver U < 7 V U > 9 V U > 9 V U < 7 V
(closed) (open) (open) (closed)
Sender U < 1,5 V I < 100 µ I < 100 U < 1,5
at 330 mA A at 18 V µA V
(closed) (open) at 18 V at 330
(open) mA
(closed)
Fault orientation: circuits shall be designed in such a way to avoid that the most likely failure mode of
any component does not close the line.
4.1.1.6 Character format
A frame shall be sent as a character string in standard asynchronous format.
The character format is shown in Figure 2.
logic 0
logic 1
start  b    b    b   b    b   b    b   b  parity  stop  idle . idle
0 1 2 3 4 5 6 7
Character length
Inter-character time
Figure 2 – Character format
Each character shall consist of one Start bit, eight Data bits b … b , one parity bit and one Stop bit.
o 7
Each data octet (b (=msb), b … b ) shall be formatted as a character and shall be sent with lsb (=b )
7 6 0 o
first.
The start bit shall be a Logic “1”.
The parity bit shall make an odd parity of the count of the Logic “0” values over the data bits and the
Parity bit.
The stop bit shall be a Logic “0”.
4.1.1.7 Synchronisation
The bits of a character shall be transmitted as one continuous stream. The leading edge of the start bit as
defined in 4.1.1.6 shall be interpreted as the start of the character and shall be used for bit and character
synchronisation. The character shall end with the stop bit.
The characters in a frame (see 4.4.1) shall be sent as one stream with an inter-character time < 2,3 ms.
4.1.2 Transceiver characteristics
4.1.2.1 Description
The following subclauses specifiy the electrical and timing requirements for senders and transmitters.
4.1.2.2 Sending part
The requirements shown in Table 2 and Figure 3 shall be met:
Table 2 – Transceiver characteristics – Sending part
Feature Requirement
Maximum closed-circuit voltage across 1,5 V at 330 mA
terminals
Maximum open-circuit leakage current 100 µA at 18 V
Maximum distortion 10 %
Rising edge
0,8 µs ≤ t ≤ 5 µs (see test set-up in
r
Figure 3)
Falling edge
0,8 µs ≤ t ≤ 5 µs (see test set-up in
f
Figure 3)
U
Ω
0,9 U
100 nF
15 V power supply
v olltage regulated
transmitter U
(ICC>400mA)
under tests
0,1 U
t
t
t
f
r
Figure 3 – Transmitter rising and falling edges

– 13 – EN 50090-5-2:2004
4.1.2.3 Receiving part
The requirements shown in Table 3 shall be met:
Table 3 – Transceiver characteristics – Receiving part
Feature Requirement
Maximum input resistance
500 kΩ
Minimum current drain per device 30 µA
Threshold voltage 8 V ± 1 V
Minimum permissible distortion 30 %

4.1.3 Physical layer services – Physical data service
This Ph-Data-service shall transfer a single octet of data between co-operating peer data link layer
entities. It shall consist of three primitives:
Ph-Data.Request this primitive shall be used to transmit a single octet
Ph-Data.Confirm this primitive shall indicate to the client layer the success or otherwise of the
transmission
Ph-Data.Indication this primitive shall convey the received octet to the receiving data link layer.
Table 4 – Mandatory and optional requirements for physical layer services
Parameter Name Request Indication Confirm
Ph-SDU
Mandatory Mandatory Not used
Ph-Result
Not used Mandatory Mandatory
Parameter Ph-SDU shall contain the octet to be transmitted (values 00h to FFh) or received. It is
mandatory, both in the Ph-Data.Request and Ph-Data.Indicate primitives. The physical layer, on receiving
the Ph-Data.Request primitive from the data link layer, shall:
• insert a start bit before the 8 data bits,
• calculate the odd parity value and insert the parity bit after the 8 data bits,
• terminate the bit string with a stop bit and
• send the 11-bit character and monitor the line for possible collision.
Upon completion of the transmission, successful or not, the Ph-Data.Confirm primitive shall carry the
Ph-Result parameter to the data link layer.
When the physical layer is not transmitting a character, it shall monitor the line for a close-circuit
condition. If this condition happens, the physical layer shall start with the reception of an 11-bit character.
If a character is received, the start bit, stop bit and the parity bit, shall be checked and if correct shall be
discarded. The character shall be delivered to the data link layer in a Ph-Data. Indication primitive and the
Ph-Result parameter shall convey the correct or incorrect reception.

Service parameter Ph-Result shall convey to the data link layer the result of a call of the Ph-Data.Request
or Ph-Data.Indication primitive, and shall have one of the following values:
Table 5 – Physical-Result parameter
Value Meaning
0 Ph-Result_ok: octet was correctly transmitted or
received
1 Ph-Result_Coll: octet was corrupted due to
collision
2 Ph-Result_Fail: octet was not correctly sent
3 Ph-Result_Nok: received octet was corrupted

4.1.4 Physical layer protocol
4.1.4.1 General
The physical layer (layer 1) shall perform the following tasks:
• generating and checking the start bit, parity bit and stop bit for each octet of the frame;
• sending each bit of each octet of the frame, while comparing the signal on the line with the intended
information;
• immediately stopping transmissions on detecting a collision, and switching to reception;
• monitoring the medium for signals, receiving characters and passing these on to the data link layer.
4.1.4.2 Octet transmission and reception
Each octet passed by the data link layer to the physical layer shall be transmitted on the medium. The
Ph-Data.Confirm primitive shall indicate whether the octet was successfully transmitted or whether it was
corrupted. If the device is not transmitting, the Ph-Data.Indication primitive shall convey each received
octet to the data link layer together with the Ph-Result indicating successful or corrupted reception of the
octet.
4.2 Medium definition
4.2.1 Topology
Devices shall be connected in multidrop mode.
Bus, ring or star topologies or any combination thereof are allowed.
4.2.2 Line
The line shall be a single twisted pair cable, shielded when necessary. The line shall carry the data
signals to all connected devices and provide power supply to the line-supplied devices.
The following requirements shall be met:

– 15 – EN 50090-5-2:2004
Table 6 – Requirements for the TP0 line
Feature Requirement
Maximum line resistance between power
12 Ω
supply and most remote device
Maximum line capacitance 250 nF
Maximum sum of device protection 150 nF
capacitance
4.2.3 Line connection
Line polarity shall be observed.
Appliances may either be hardwired to the line or may be attached to it by means of a connector.
4.2.4 Repeater
A repeater shall consist of two receivers, two transmitters and optionally one or two power supplies.
Between any two TP0 devices, a maximum of two repeaters is allowed. The information flow transfer
logic shall be transparent to data. A short-circuit detected on one segment shall not be transmitted on the
other segment for longer than 195 ms. A segment shall be regarded as short-circuited when it is in close-
circuit state for longer than 165 ms. The turning logic shall not disturb collision detection and arbitration
between devices on different segments and shall not increase distortion by more than 5 %.
Primary segment Secondary segment
100 ms 100 ms
2 000 ms 195 ms max
Figure 4 – Repeater maximum transition time
4.2.5 Medium installation requirements
The medium shall be supplied at Safety or Protective Extra Low Voltage (SELV or PELV); with an
insulating sheath having a dielectric strength in compliance to EN 50090-2-2.

4.2.6 General hardware requirements
The requirements shown in Table 7 shall be met in compliance to EN 50090-2-2 and EN 50090-9-1:
Table 7 – General hardware requirements
Feature Requirement
Maximum coupling capacitance between line 100 pF
and all other I/Os
Line/earth and mains/earth isolation Compliance to the relevant standards
Decoupling capacitors line / ground or mains / Allowed but complying to the relevant standards
ground
Dielectric strength line / 230 V mains 4 kV for 1 min at 50 Hz
Dielectric strength line/metal masses connected 2 kV for 1 min at 50 Hz
to protection conductor
Insulation resistance line / 230 V mains
5 MΩ at 500 V
Minimum creepage distance line / 230 V mains 8 mm
Minimum creepage distance line/metal masses 3 mm
connected to protection conductor

4.3 Power feeding service
4.3.1 General
The used modulation technique shall allow connection to the line of devices supplied with power from the
line, and devices supplied by an external source (e.g. 230 V mains). The maximum line-supply current
shall not exceed 150 mA.
Line-supplied devices shall ensure retention of required data during a line-closed-circuit condition of up-
to-200 ms.
4.3.2 Power feeding device types
Supplying power to a device may be achieved via:
I. line (bus) power,
II. local mains,
III. local batteries or other independent power source.
All devices connected to the network are permitted to use line power provided that they meet the
requirements of 4.3.3.
4.3.3 Factor C (current consumption)
As regards current consumption the following requirements shall be met:

– 17 – EN 50090-5-2:2004
Table 8 – Current consumption requirements
Type of device Average (quiescent) Peak (reception)
a
Devices supplied via line 0,5 mA maximum 0,825 mA maximum
b
Devices supplied via external source 100 µA maximum 165 µA maximum
a
For devices supplied via the line, C shall be calculated for the average and peak current drain and the higher of the
two values shall be rounded up to the next higher integer value.
b
For devices not supplied via the line, a fixed C value of 0,2 shall be taken into account.

In an installation, the C factor shall never exceed 300 and the C factor of the power supply unit shall
always exceed the total C factor of the installed devices.
4.3.4 Line power supply general requirements
The following requirements shall be met:
• power on/off switching shall be provided. The leakage current shall be lower than 1 mA on short
circuit;
• power supply shall withstand a permanent line short-circuit condition and shall recover its
characteristics within 5 min after short-circuit suppression;
• the sum of the line-supplied device capacitance values shall be lower than 40 mF, corresponding to a
power-on time of 3 s maximum;
• the operation voltage for line-supplied devices shall be at least 9,5 V.
4.3.5 Power supply voltage
The requirements shown in Table 9 and Figure 5 shall be met:
Table 9 – Power supply voltage
Feature Requirement
No-load voltage 15,5 V ± 10 % (static, I < 100 µA)
Minimum voltage under load 13,5 V at C x 0,825 mA (250 mA if C = 300),
(200 ms minimum current pulse duration)
12 V at 250 mA (2 ms minimum current pulse)
Closed-circuit current 300 mA ± 10 % independently of power supply's
C
(200 ms minimum with 5,1 V and 1 V max.)

The requirements as stated in Table 9 and Figure 5 shall be complied with for at least the indicated time
duration T .
min
U
(V)
Forbidden area
17,05
15,5
13,95
C * 0,825 mA
13,5 Cmax = 300
Tmin 200 ms
12 Tmin 2 ms
These points are
independent of
Power Supply’s C
Forbidden area
5,1
Tmin
200 ms
I
150 250 270 300 330
(mA)
< 100 µ Α
Figure 5 – TP0 power supply gauge
4.3.6 Dynamic characteristics
4.3.6.1 Dynamic internal resistance of current generator
The dynamic internal resistance of the current generator shall be maximum 1 kΩ, measured at 50 Hz,
(see test set-up in Figure 6). ΔU shall be ≥ 10 V in the linear area of the curve.

U
x
I
y
U
TP0
ΔU
power supply
Current regulated load
under test
R=ΔU/ΔI
0 to 350 mA 50 Hz
ΔI
I
Figure 6 – Power supply dynamic internal resistor measuring test set-up
4.3.6.2 Switching from voltage to current mode
The following requirements shall be met:
• rising edge for voltage shall be minimum 0,6 µs, maximum 5 µs;
• over-current shall be maximum 30 % of current flowing from power supply during maximum 5 µs.
Measuring shall be carried out with a standard transmitter (t = 1,1 µs ± 20 %, t = 1,5 µs ± 20 % according
r f
to 4.1.2). See test set-up in Figure 7.

– 19 – EN 50090-5-2:2004
U
0,9 U 0,9 U
U
0,1 U 0,1 U
I
t f t r
t
U
TP0
5 µ s max.
power supply
Standard transmitter
under tests
I
Max. - 0,3 I
0,9 I
I
0,1 I
t r
t
Figure 7 – Falling edge and over-current measurements
4.3.6.3 Additional requirements
The above mentioned specifications are given for a mains powered system. A system with battery
back-up, may be designed so that parameters "no-load voltage", "C on one segment", "line resistance"
and "line voltage drop" may be different during a power down. Their arrangement shall however ensure a
minimum noise margin of 0,5 V in open circuit state for all points of the system (opened voltage 9,5 V
minimum). The resulting installation constraints shall be clearly explained in the product documentation.
Peak supply current measurement shall be carried out at least 800 ms after the beginning of transmission
of frames to the device under test. These frames shall contain the same number of “0” and “1” separated
by a 22 ms inter frame time.
Installation rules requires that for PELV circuits the negative pole of the power supply shall be grounded.
The link from the line to the ground shall be made at one point (and only one point) of the TP0 power
supply. In the case when one line is composed of more than one segment without isolation between
segments, only one point shall be grounded.

4.3.7 Distributed power supply (DPS)
4.3.7.1 Overview
D5(S)
D16(S)
D4(R)
D2(P)
D3(R)
Key
D1(S)
D: device
(S): device with DPS
(R): device remotely powered from the bus
(P): passive device (neither DSP nor powered from the bus)

Figure 8 – TP0 Network with distributed power supply
The use of the Distributed Power Supply (DPS) on a TP0 network may be used in the following cases:
• small networks with less than 16 devices connected to the bus (regardless of their type - S, R or P -
see Figure 8);
• devices separated by short cable distances (250 m to 1400 m depending on the number of devices
with activated DPS);
• when only a few devices have to be powered from the bus. The available average supply current is
limited to 10 to 60 mA depending on the number of devices with DPS.
Automatic Over-Current Protection (OCP) function shall be implemented in devices with DPS feature. The
number of devices with activated DPS shall be limited to maximum 8. If more devices with DPS capability
are connected to the network, the OCP function shall automatically disable DPS in some devices in order
to limit the resulting signal current (closed circuit) to a maximum value of 176 mA. Devices with disabled
DPS shall behave like passive P devices (see Figure 8).
Devices with DPS feature shall allow manual disabling of the DPS functionality (for instance by means of
a jumper or configuration of a parameter).

– 21 – EN 50090-5-2:2004
4.3.7.2 Requirements for one supplying DPS device
The requirements showing in Table 10 and Figure 9 shall be met:
Table 10 – Requirements for one supplying
...