Ashida ADR241B, Instruction Manual

Page: 135 / 272

Doc ID : ADR241B-DO_IM_01
Ref ID : ADR241B/IM/CS
Rev No. : 06
Page No. : 135 of 272
ADR241B
Initialization (reset)
Time synchronisation
Event record extraction
General interrogation
Cyclic measurements
General commands
Disturbance record extraction
7.5 Physical Connection and Link Layer
For connecting on IEC 60870-5-103 there are two options:
Front USB Port.
Rear serial port - for permanent SCADA connection via EIA (RS) 422.
The IED address, Parity and Baud rate can be selected using the front panel menu.
7.6 Initialisation
Whenever the device has been powered up, or if the communication parameters have been
changed, a reset command is required to initialize the communications. The device will
respond to either of the two reset commands; Reset CU or Reset FCB (Communication Unit
or Frame Count Bit). The difference between the two commands is that the Reset CU
command will clear any unsent messages in the transmit buffer, whereas the Reset FCB
command does not delete any messages.
The device 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 relay will also produce a power up event, when the relay is powered up.
7.7 Time Synchronisation
The time and date can be set using the time synchronisation feature of the IEC 60870-5-103
protocol. The device will correct the transmission delay depending on communication speed.
For this, transmission time, required for the time synchronization frame from the Master to
IED, considering current baud rate is added in the received time.
The device will correct the transmission delay depending on baud rate. If the time
synchronisation message is sent as a send/confirm message then the device will respond
with a confirm message. A time synchronisation Class 1 event will be generated/produced
whether the time-synchronisation message is sent as a send confirm or a broadcast
(send/no reply) message.