Note:
MODBUS conv
ention is to document register addresses as ordinal values whereas the actual protocol addresses are literal
values. The MiCOM relays begin their register addresses at zero. Therefore, the first register in a memory page is register
address zero. The second register is register address 1 and so on.
Note:
The page number notation is not par
t of the address.
6.4.5 EVENT EXTRACTION
The device supports two methods of event extraction providing either automatic or manual extraction of the
stor
ed event, fault, and maintenance records.
6.4.5.1 AUTOMATIC EVENT RECORD EXTRACTION
The automatic extraction facilities allow all types of record to be extracted as they occur. Event records are
extracted in sequential or
der including any fault or maintenance data that may be associated with the event.
The MODBUS master can determine whether the device has any events stored that have not yet been extracted.
This is performed by reading the status register 30001 (G26 data type). If the event bit of this register is set then the
device has non-extracted events available. To select the next event for sequential extraction, the master station
writes a value of 1 to the record selection register 40400 (G18 data type). The event data together with any fault/
maintenance data can be read from the registers specified below. Once the data has been read, the event record
can be marked as having been read by writing a value of '2' to register 40400.
6.4.5.2 MANUAL EVENT RECORD EXTRACTION
There are three registers available to manually select stored records and three read-only registers allowing the
number of stor
ed records to be determined.
● 40100: Select Event
● 40101: Select Fault
● 40102: Select Maintenance Record
For each of the above registers a value of 0 represents the most recent stored record. The following registers can
be read to indicate the numbers of the various types of record stored.
● 30100: Number of stored records
● 30101: Number of stored fault records
● 30102: Number of stored maintenance records
Each fault or maintenance record logged causes an event record to be created. If this event record is selected, the
additional registers allowing the fault or maintenance record details will also become populated.
6.4.5.3 RECORD DATA
The location and format of the registers used to access the record data is the same whether they have been
selected using either automatic or manual extraction.
Event Description
MODBUS
Addr
ess
Length Comments
Time and Date 30103 4 See G12 data type description
Event Type 30107 1 See G13 data type description
Event Value 30108 2
Nature of value depends on event type. This will contain the status as a binary flag
for contact, opto-input, alarm, and protection events.
P24xM Chapter 16 - Communications
P24xM-TM-EN-2.1 339
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