PRON NA60-CB0
Version 2.00
Page: 9 of 15
PRON NA60-CB0 IEC 870-5-103
2.2 Initialisation
Whenever the relay has been powered up, or if the communication parameters have been changed a reset
command is required to initialise 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 following information will be contained in the data section of this ASDU:
Internal Software ID: internal Firmware ID
ASCII ID: Relay model
2.3 Time synchronisation
The relay time and date can be set using the time synchronisation feature of the IEC60870-5-103 protocol. The
relay will correct for the transmission delay as specified in IEC60870-5-103.
2.4 Spontaneous events
The events created by the relay will be passed using the standard function type/information numbers to the
IEC60870-5-103 master station. Private codes are not used, thus any events that cannot be passed using the
standardised messages will not be sent.
Events are categorised using the following information:
•
Common Address
•
Function Type
•
Information number
The common address is used to differentiate in circumstances where the relay produces more events of a certain
type than can be passed using the standardised messages.
For example if the relay produces starts and trips for three stages of overcurrent only two stages can be passed
using the standardised messages.
Using the different common address for two of the overcurrent stages allows each stage to be indicated.
2.5 General interrogation
The GI request can be used to read the status of the relay, the function numbers, information numbers and
common address offsets that will be returned during the GI cycle are indicated in 2.11.
2.6 Cyclic measurements
The relay will produce measured values using ASDU 3 on a cyclical basis, this can be read from the relay using a
Class 2 poll (note ADSU 9 is not used).
It should be noted that the measurands transmitted by the relay are sent as a proportion of either 1.2 or 2.4 times
the rated value of the analogue value. The selection of either 1.2 or 2.4 for a particular value is indicated in 2.11.
