Chapter 4 - 7SR45 Data Communications Definitions
© 2018 Siemens Protection Devices Limited
Chapter 4 Page 8 of 20
Section 4: IEC 60870-5-103 Definitions
4.1
Introduction
This section describes the IEC 60870-5-103 protocol implementation in the relays. This protocol is
used for the communication with Reydisp software and can also be used for communication with a
suitable control system. The control system or local PC acts as the master in the system with the relay
operating as a slave responding to the master's commands. The implementation provides event
information, time synchronising, commands and measurands and also supports the transfer of
disturbance records.
This protocol can be set to use any or all of the relays hardware interfaces (USB, RS485) where fitted
and is the standard protocol used by the USB port. The relay can communicate simultaneously on all
ports regardless of protocol used.
The Station Address of the port being used must be set to a suitable address within the range 0 - 254
to enable communication. This can be set by the
Communications Menu: -xxxxx Stn Addr
setting.
4.2
Cause of Transmission
The cause of transmission (COT) column of the “
Information Number and Function
” table lists
possible causes of transmission for these frames. The following abbreviations are used:
Abbreviation
Description
SE
spontaneous event
GI
general interrogation
Loc
local operation
Rem
remote operation
Ack
command acknowledge
Nak
Negative command acknowledge
NOTE
Events listing a GI cause of transmission can be raised and cleared; other events are raised only.
4.2.1
Application Service Data Unit (ASDU) Type
The Application Service Data Unit (ASDU) column of the
“Information Number and Function”
table
lists the possible ASDUs returned for a point.
ASDU #
Description
1
Time tagged message (monitor direction)
2
Time tagged message (relative time) (monitor direction)
4
Time-tagged measurands with relative time
5
Identification message
6
Time synchronisation
7
General Interrogation Initialization
9
Measurands II
20
General command
4.2.2
Point List
The following sub-sections contain tables listing the data points available via the IEC60870-5-103
protocol.
Note that not all events are available on all relay models.