P54x/EN SC/La4 SCADA Communications
(SC) 13-22
MiCOM P543, P544, P545 & P546
SC
The programmable scheme logic settings can be uploaded and downloaded to and from the
relay using this mechanism. If it is necessary to edit the settings MiCOM S1 Studio must be
used as the data format is compressed. MiCOM S1 Studio also performs checks on the
validity of the settings before they are downloaded to the relay.
3. IEC 60870-5-103 INTERFACE
The IEC 60870-5-103 interface is a master/slave interface with the relay as the slave device.
The relay conforms to compatibility level 2; compatibility level 3 is not supported.
The following IEC 60870-5-103 facilities are supported by this interface:
Initialization (reset)
Time synchronization
Event record extraction
General interrogation
Cyclic measurements
General commands
Disturbance record extraction
Private codes
3.1 Physical connection and link layer
Two
connection options are available for IEC 60870-5-103, either the rear EIA(RS)485 port
or an optional rear fiber optic port. Should the fiber optic port be fitted the selection of the
active port can be made via the front panel menu or the front Courier port, however the
selection will only be effective following the next relay power up.
For either of the two modes of connection it is possible to select both the relay address and
baud rate using the front panel menu/front Courier. Following a change to either of these
two settings a reset command is required to re-establish communications, see reset
command description below.
3.2 Initialization
Whe
never the relay has been powered up, or if the communication parameters have been
changed a reset command is required to initialize the communications. The relay will
respond to either of the two reset commands (Reset CU or Reset FCB), the difference being
that the Reset CU will clear any unsent messages in the relay’s transmit buffer.
The relay will respond to the reset command with an identification message ASDU 5, the
Cause Of Transmission COT of this response will be either Reset CU or Reset FCB
depending on the nature of the reset command. The content of ASDU 5 is described in the
IEC 60870-5-103 section of the menu database, P54x/EN MD.
In addition to the above identification message, if the relay has been powered up it will also
produce a power up event.
3.3 Time synchronization
The rel
ay time and date can be set using the time synchronization feature of the
IEC 60870-5-103 protocol. The relay will correct for the transmission delay as specified in
IEC 60870-5-103. If the time synchronization message is sent as a send/confirm message
then the relay will respond with a confirm. Whether the time-synchronization message is
sent as a send confirm or a broadcast (send/no reply) message, a time synchronization
Class 1 event will be generated/produced.
If the relay clock is being synchronized using the IRIG-B input then it will not be possible to
set the relay time using the IEC 60870-5-103 interface. An attempt to set the time via the
interface will cause the relay to create an event with the current date and time taken from the
IRIG-B synchronized internal clock.
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