Extraction Mechanism; Interface Registers - GE MiCOM P40 Agile Technical Manual

SCADA Communications
MiCOM P40 Agile P442, P444
3.6 Disturbance record extraction
The relay provides facilities for both manual and automatic extraction of disturbance records.
The extraction mechanisms are explained below:
3.6.1

Extraction mechanism

Records extracted over MODBUS from Px40 platform relays will be presented in
COMTRADE format. This involves extracting an ASCII text configuration file and then
extracting a binary data file.
Each file is extracted by reading a series of data pages from the relay. The data page is
made up of 127 registers, giving a maximum transfer of 254 bytes per page.
3.6.1.1

Interface registers

The following set of registers is presented to the master station to support the extraction of
uncompressed disturbance records:
MODBUS Register
3x00001
3x00800
3x00801
4x00250
4x00400
3x00930 – 3x00933
Name
Status register
o
N of stored
disturbances
Unique identifier of the
oldest disturbance
record
Manual disturbance
record selection
register
Record selection
command register
Record time stamp
Description
Provides the status of the relay as bit flags:
b0 – Out of service
b1 – Minor self test failure
b2 – Event
b3 – Time synchronization
b4 – Disturbance
b5 – Fault
b6 – Trip
b7 – Alarm
b8 to b15 – Unused
A '1' on b4 indicates the presence of a
disturbance.
Indicates the total number of disturbance
records currently stored in the relay, both
extracted and unextracted.
Indicates the unique identifier value for the
oldest disturbance record stored in the relay.
This is an integer value used in conjunction
o
with the 'N of stored disturbances' value to
calculate a value for manually selecting
records.
This register is used to manually select
disturbance records. The values written to
this cell are an offset of the unique identifier
value for the oldest record. The offset value,
which ranges from 0 to the N
disturbances – 1, is added to the identifier of
the oldest record to generate the identifier of
the required record.
This register is used during the extraction
process and has a number of commands.
These are:
b0 – Select next event
b1 – Accept event
b2 – Select next disturbance
record
b3 – Accept disturbance record
b4 – Select next page of
disturbance data
b5 – Select data file
These registers return the timestamp of the
disturbance record.
P44x/EN SC/Hb6
(SC) 12-23
o
of stored