ISA 50.02-3 : 1997

Introduction
1 Scope
   1.1 Specifications
   1.2 Conformance
2 Normative references
3 Definitions
   3.1 Reference model definitions
   3.2 Service convention definitions
   3.3 Data Link Service definitions
4 Symbols and abbreviations
5 Conventions
   5.1 General conventions
   5.2 Parameters
   5.3 Identifiers
6 Overview of the Data Link Service
   6.1 Overview of DL-subnetwork structuring
   6.2 Overview of DL-naming (addressing)
7 Types and classes of Data Link Service
8 Quality of Service (QoS) attributes common to multiple types
   of Data Link Service
   8.1 DLL priority (dynamic QoS attribute)
   8.2 DLL maximum confirm delay (dynamic QoS attribute)
   8.3 DLPDU authentication (semi-static QoS attribute)
   8.4 DL-scheduling-policy (semi-static QoS attribute)
   8.5 DL-timeliness (dynamic DLCEP QoS attributes)
9 Facilities of the DL (SAP)-address, queue and buffer
   management Data Link Service
10 Model of the DL (SAP)-address, queue and buffer management
   Data Link Service
11 Sequence of primitives at one DLSAP
   11.1 Constraints on sequence of primitives
12 DL (SAP)-address, queue and buffer management facilities
   12.1 Create
   12.2 Delete
   12.3 Bind
   12.4 Unbind
   12.5 Put
   12.6 Get
13 Facilities of the connection-mode Data Link Service
14 Model of the connection-mode Data Link Service
   14.1 DLCEP-identification
   14.2 Model of a peer DLC
   14.3 Model of a multi-peer DLC
15 Quality of connection-mode service
   15.1 Determination of QoS for connection-mode service
   15.2 Definition of QoS parameters
16 Sequence of primitives
   16.1 Concepts used to define the connection-mode
        DL-service
   16.2 Constraints on sequence of primitives
17 Connection establishment phase
   17.1 Function
   17.2 Types of primitives and parameters
   17.3 Sequence of primitives
18 Connection release phase
   18.1 Function
   18.2 Types of primitives and parameters
   18.3 Sequence of primitives when releasing an established
        DLC/DLCEP
   18.4 Sequence of primitives in a DLS-user rejection of a
        DLC / DLCEP establishment attempt
19 Data transfer phase
   19.1 Queue data transfer
   19.2 Buffer data transfer
   19.3 Reset
   19.4 Subscriber query
20 Facilities of the connectionless-mode Data Link Service
21 Model of the connectionless-mode Data Link Service
   21.1 Model of DL-connectionless-mode unitdata transmission
   21.2 Model of DL-connectionless-mode unitdata exchange
22 Quality of connectionless-mode service
   22.1 Determination of QoS for connectionless-mode service
   22.2 Definition of QoS parameters
23 Sequence of primitives
   23.1 Constraints on sequence of primitives
   23.2 Relation of primitives at the end-points of
   connectionless service
   23.3 Sequence of primitives at one DLSAP
24 Connectionless-mode functions
   24.1 Data transfer
   24.2 Data exchange
   24.3 Listener query
25 Facilities and classes of the time and scheduling guidance
   Data Link Service
26 Model of the time and scheduling guidance Data Link
   Service
27 Quality of scheduling guidance service
28 Sequence of primitives at one DLE
   28.1 Constraints on sequence of primitives
29 Scheduling guidance functions
   29.1 DL-time
   29.2 Compel service
   29.3 Schedule sequence
   29.4 Cancel schedule
   29.5 Subset sequence
Annex A - (normative) DL-Management service definition
      A.1 Scope and inheritance
      A.2 Facilities of the DL-management service
      A.3 Model of the DL-management service
      A.4 Constraints on sequence of primitives
      A.5 Set
      A.6 Get
      A.7 Action
      A.8 Event

Defines the characteristics of a conceptual data link service suitable for time-critical communications, and supplements the OSI basic reference model in guiding the development of data link protocols. Time-critical represents the presence of a time-window, within which one or more specified actions are required to be completed with some defined level of certainty. Failure to complete specified actions within the time-window risks failure of the applications requesting the actions, with attendent risk to equipment, plant, and possibly human life.