Data Storage; General; Event Records; Waveform Records - Siemens 7SR224 Technical Manual

6.4

Data Storage

6.4.1

General

The relay stores three types of data: relay event records, analogue/digital waveform records and fault records.
Data records are backed up in non-volatile memory and are permanently stored even in the event of loss of
auxiliary d.c. supply voltage.
6.4.2

Event Records

The event recorder feature allows the time tagging of any change of state (Event) in the relay. As an event
occurs, the actual event condition is logged as a record along with a time and date stamp to a resolution of 1
millisecond. There is capacity for a maximum of 5000 event records that can be stored in the relay and when the
event buffer is full any new record will over-write the oldest. Stored events can be erased from the front fascia via
DATA STORAGE>Clear Events setting or using Reydisp Evolution via Relay > Events > Reset Events.
The following events are logged:
Change of state of Binary outputs.
Change of state of Binary inputs.
Change of Settings and Settings Group
Change of state of any of the control functions of the relay.
All events can be retrieved over the data communications channel(s) and can be displayed in the 'Reydisp
Evolution' package in chronological order, allowing the sequence of events to be viewed. Events are also made
available spontaneously to an IEC 60870-5-103, Modbus RTU or DPN 3.0 compliant control system.
For a complete listing of events available in each model, refer to Technical Manual section 4 'Data Comms'.
6.4.3

Waveform Records.

Relay waveform storage can be triggered either after user selected relay operations, from the relay fascia, from a
suitably programmed binary input or via the data comms channel(s). The stored analogue and digital waveforms
illustrate the system and relay conditions at the time of trigger.
In total the relay provides 10 seconds of waveform storage, this is user selectable to 1 record of 10 seconds
duration, 2 records of 5 seconds duration, 5 records of 2 seconds duration or 10 records of 1 second duration.
When the waveform recorder buffer is full any new waveform records will over-write the oldest. The most recent
record is Waveform 1.
As well as defining the stored waveform record duration the user can select the percentage of the waveform
storage prior to triggering.
The waveform recorder samples at a rate of 32 samples per cycle (1600Hz).
Stored waveforms can be erased using the DATA STORAGE>Clear Waveforms setting or using Reydisp
Evolution via Relay > Waveform > Reset Waveform Records.
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7SR224 Argus Description of Operation
Chapter 1 Page 66 of 70