BS EN 60870-5-2:1994

Committees responsible
National foreword
Specification
Introduction
1. Scope and object
1.1 Scope
1.2 Object
2. Normative references
3. Formats and structures of standard transmission
       frames
3.1 Format FT 1.1
3.2 Format FT 1.2
3.3 Format FT 2
3.4 Format FT 3
4. Selection primitives and elements of transmission
       procedures
4.1 SEND/NO REPLY service
4.1.1 Service procedure
4.1.2 Transmission procedure
4.2 SEND/CONFIRM service
4.2.1 Service primitives
4.2.2 Transmission procedure
4.3 REQUEST/RESPOND service
4.3.1 Service primitives
4.3.2 Transmission procedures
5. Unbalanced transmission
5.1 Specification of length, control and address fields
5.1.1 Length field
5.1.2 Control field
5.1.3 Address field
5.2 Unbalanced transmission services
5.3 Unbalanced transmission procedures
5.3.1 SEND/NO procedures
5.3.2 Undisturbed SEND/CONFIRM procedures
5.3.3 Disturbed SEND/CONFIRM procedures
5.3.4 Undisturbed REQUEST/RESPOND procedures
5.3.5 Disturbed REQUEST/RESPOND procedures
6. Balanced transmission
6.1 Specification of length, control and address fields
6.1.1 Length field
6.1.2 Control field
6.1.3 Address field
6.2 Balanced transmission services
6.3 Balanced transmission procedures
6.3.1 SEND/NO REPLY procedures
6.3.2 Undisturbed SEND/CONFIRM procedures
6.3.3 Undisturbed procedures with data flow control
6.3.4 Disturbed SEND/CONFIRM procedures
Annex
A. Time out interval for repeated frame transmission
Tables
1. Unbalanced transmission, function codes of control
     field in messages sent from primary (PRM = 1)
2. Unbalanced transmission, function codes of control
     field in messages sent from secondary (PRM = 0)
3. Balanced transmission, function codes of control
     field in messages sent from primary (PRM = 1)
4. Balanced transmission, function codes of control
     field in messages sent from secondary (PRM = 0)
Figures
1. Relationship between service primitives and
     transmission procedures for basic link services
2. Example of the interaction between a polling
     procedure and an event-initiated transmission
3. Unbalanced transmission procedures, undisturbed
     SEND/CONFIRM procedures
4. Unbalanced transmission procedures, disturbed SEND/
     CONFIRM procedure
5. Unbalanced transmission procedures, undisturbed
     REQUEST/RESPOND procedures
6. Unbalanced transmission procedures, undisturbed
     REQUEST/RESPOND procedures
7. Unbalanced transmission procedures, undisturbed
     REQUEST/RESPOND procedures
8. Unbalanced REQUEST/RESPOND transmission procedures,
     disturbed REQUEST frame
9. Unbalanced REQUEST/RESPOND transmission procedures,
     disturbed RESPOND frame
10. Example of the interaction of service primitives and
     transmission procedures in a balanced system
11. Balanced transmission procedures, undisturbed SEND/
     CONFIRM procedures
12. Balanced transmission procedures, data flow control
13. Balanced transmission procedures, disturbed SEND
     frame
14. Balanced transmission procedures, disturbed SEND and
     ignored CONFIRM frame
15. Balanced transmission procedures, disturbed CONFIRM
     frame
16. Balanced transmission procedures, disturbed channel
     in one direction
A.1 Unbalanced transmission procedures, disturbed
     primary frame
A.2 Unbalanced transmission procedures, disturbed
     secondary frame
A.3 Balanced transmission procedures, disturbed primary
     frame
A.4 Balanced transmission procedures, disturbed
     secondary frame

Requirements with coded bit serial data transmission for monitoring and controlling geographically widespread processes.

This section of IEC 870-5 applies to telecontrol equipment and systems with coded bit serial data transmission for monitoring and controlling geographically widespread processes.

The defined link procedures are restricted to message transmission sequences operating with size 1 windows. This means that the link layer of the primary station (station that initiates a message transfer) accepts a request for a new message transfer only when a previously accepted request for a message transfer is terminated either successfully or with an error indication. The procedures are applicable to balanced and unbalanced transmission in telecontrol systems using half duplex or duplex transmission channels.