BS EN 61784-2-2014 pdf download.Industrial communication networks Profiles Part 2: Additional fieldbus profiles for real-time networks based on ISO/1EC 8802-3.
A network that includes real-time communication and Is based on the ISOIIEC 8802-3 standard is called a Real-time Ethernet (RTE) network. Users of RTE networks have different requirements for different applications. In order to satisfy these requirements in an optimal way RTE communication networks complying with CPs described in this standard will exhibit different performance.
Performance indicators (specified in 5.3) shall be used to specify capabilities of an RTE end device and an RTE communication network as well as to specify requirements of an application. Performance indicators will be used as a set of interaction means between the user of the RTE CP and the manufacturer of RTE CP compliant RTE end devices and network components. Subclause 5.2 specifies the application requirements view.
Performance indicators represent
a) capabilities of an RTE end device,
b) capabilities of an RTE communication network.
C) as well as requirements of an application.
A consistent set of performance indicators (specified in 5.3) is used to represent the RTE capabilities. Some of the performance indicators are interdependent; in this case some indicator values depend on the value of others to provide a consistent set.
NOTE The Interdependence Is due to physical or logical constraints, which are not changeable. For example it Is not possible to have the indicators “Throughput RTE (which would use 90 % of the total bandwidth)” and
•‘Throughput non-RTE (90 %)“ at the same time because that would describe a transmission load of 180 %,
No general boundary values to specify RTE performance are specified for the indicators in this standard, but device suppliers need to specify boundary values for a CP-based product if they claim to be compliant to this standard.
Technology specific CPF subclauses specify
a) selection of performance indicators Out of possible performance indicators defined in 5.3 relevant to a given CP, optionally with their individual limits or ranges,
b) interdependence between performance indicators,
c) optionally, lists with consistent performance indicators values.
Each of the lists has one or more leading performance indicators. The leading performance indicators are preset to a fixed value (typically optimized to have the best overall performance). The other performance indicators in the list are shown with their related consistency limits,
d) optionally, a more comprehensive representation of the relation between performance indicators (Figure 1 shows an example of a graphical representation).
The supplier of RTE end devices and RTE communication networks shall provide at least one consistent set of performance indicators. The boundary values given by the supplier should be based on conformance test principles specified in Clause 6.
NOTE I A set of lists with consistent performance indicators is only given when interdependence between performance Indicators exists.
NOTE 2 Ii is possible that applications have requirements where one particular indicator has higher importance than all the others. Such applications will find useful the opportunity to select the consistent indicator list with the relevant leading Indicator, Other applications may have requirements where several indicators are of equally high importance. For such applications, a graphical or otherwise more comprehensive representation of the relation between consistent Indicators is more appropriate. Figure 1 is an example of a graphical representation of consistent indicators given by a CP.
NOTE 3 RTE end devices are designed under the discretion of manufactures of such a device. Therefore no assumption could be made how many RTE end-stations (network rnterlaces) are build in one device. In order to achieve comparable performance indicators from the application perspective the performance indicators are build on RTE end-stations not on RTE devices
5.2 Application requirements
The capabilities of an RTE communication network are specified in 5.3 as indicators. The indicators are used to match application requirements to the capabilities of components compliant to one or more CP(s) of this part of IEC 61784.
A profile is suitable if its indicator values at least meet the required indicator values.
NOTE 1 Sophisticated requirements are likely to find a smaller number of matching profiles, NOTE 2 A principle for selecting the matching CP is described In ISO 15745-1.
The application-dependent class should be a subset of a CP xly to be suitable for this
application.
5.3 Performance indicators
5.3.1 Delivery time.BS EN 61784-2-2014 pdf download.