BS EN 61158-2-2014 pdf download.Industrial communication networks Fieldbus specifications
Part 2: Physical layer specification and service definition.
where
class — shall specify the PhlCl component of the PhIDU.
For a PH-DATA request, its possible values shall be:
START-OF-ACTIVITY — transmission of the PhPDUs which precede Ph-user data shall commence;
DATA — the single-octet value of the associated data parameter shall be transmitted as part of a continuous correctly formed transmission; and
END-OF-DATA-AND-ACTIVITY — the PhPDUs that terminate Ph-user data shall be transmitted after the last preceding octet of Ph-user data, culminating in the cessation of active transmission.
For a PH-DATA indication, its possible values shall be:
START-OF-ACTIVITY — reception of an apparent transmission from one or more PhEs has commenced;
DATA — the associated data parameter was received as part of a continuous correctly formed reception;
END-OF-DATA — the ongoing continuous correctly formed reception of Ph-user data has concluded with correct reception of PhPDUs implying END-OF-DATA; END-OF-ACTIVITY — the ongoing reception (of an apparent transmission from one or more PhEs) has concluded, with no further evidence of PhE transmission: and END-OF-DATA-AND-ACTIVITY — simultaneous occurrence of END-OF-DATA and END-OF- ACTIVITY.
data — shall specify the PhID component of the PhIDU. It consists of one octet of Ph-user- data to be transmitted (PH-DATA request) or which was received successfully (PH-DATA indication).
status — shall specify either success or the locally detected reason for inferring failure.
The PH-DATA confirm primitive shall provide the critical physical timing feedback necessary to inhibit the DLE from starting a second transmission before the first is complete. The final PH-DATA confirm of a transmission shall not be issued until the PhE has completed the transmission.
5.2.2 Notification of PhS characteristics
The PhE has the responsibility for notifying the DLE of those characteristics of the PhS that may be relevant to DLE operation. The PhE shall do this by issuing a single Ph-CHARACTERISTICS indication primitive at each of the PhEs PhSAPs at PhE start-up.
5.2.3 Transmission of Ph-user-data
The PhE shall determine the timing of all transmissions. When a DLE transmits a sequence of PhSDUs, the OLE shall send the sequence of PhSDUs by making a well-formed sequence of PH-DATA requests. consisting of a single request specifying START-OF-ACTIVITY, followed by 3 to 300 consecutive requests, inclusive, specifying DATA, each conveying a PhSDU, and concluded by a single request specifying END-OF-DATA-AND-ACTIVITY.
The PhE shall signal its completion of each PH-DATA request, and its readiness to accept a new PH-DATA request, by issuing a PH-DATA confirm primitive; the status parameter of the PH-DATA confirm primitive shall convey the success or failure of the associated PH-DATA request. A second PH-DATA request shall not be issued by the DLE until after the PH-DATA confirm corresponding to the first request has been issued by the PhE.
5.2.4 Reception of Ph-user-data
The PhE shall report a received transmission with a well-formed sequence of PH-DATA indications, which shall consist of
a) a single indication specifying START-OF-ACTIVITY; followed by consecutive indications specifying DATA, each conveying a PhSDU: followed by a single indication specifying END- OF-DATA; and concluded by a single indication specifying END-OF-ACTIVITY; or
b) a single indication specifying START-OF-ACTIVITY; followed by consecutive indications specifying DATA, each conveying a PhSDU; followed by a single indication specifying END-
OF-DATA-AND-ACTIVITY; or
C) a single indication specifying START-OF-ACTIVITY: optionally followed by one or more consecutive indications specifying DATA, each conveying a PhSDU; and concluded by a single indication specifying END-OF-ACTIVITY.
This last sequence is indicative of an incomplete or incorrect reception. Detection of an error in the sequence of received PhPDUs. or in the PhEs reception process, shall disable further PH-DATA indications with a class parameter specifying DATA, END-OF-DATA, or END-OF-DATA- AND-ACTIVITY until after both the end of the current period of activity and the start of a subsequent period of activity have been reported by PH-DATA indications specifying END-OFACTIVITY and START-OF-ACTIVITY, respectively.
5.3 Type 2: Required services
5.3.1 General
Subclause 5.3 defines the required physical service (PhS) primitives and constraints on their use.BS EN 61158-2-2014 pdf download.