Data Storage; Fault Records; Waveform Records; Event Records - Siemens 7SG164 Ohmega 400 Series Manual

The time and date is also displayed.
Where appropriate, additional meter displays are available depending upon the functions supplied with the
relay. These will be described in the relevant sections.

7 Data Storage

Data records are available in three forms, namely fault records, waveform records and event
records. All records are stamped with time and date. The relay incorporates a real time clock
feature which keeps time even when the relay is de-energised.
Time and date can be set either via the relay fascia using appropriate commands in the System
Configuration Menu, or via the communications interface. In the latter case, relays in a
communications network can be synchronised by a global command. Alternatively, time can be
synchronised via the IRIG B-12x interface in the relay.

7.1 Fault Records

When issuing a trip output under fault conditions, the relay illuminates the relevant LED(s) and, stores a fault
record.
This fault record contains the date and time of the occurrence, the active setting group, the flags raised and
the distance to fault (if fault location is enabled).
The fault record is viewed in the 'Fault Data Display Mode' of the menu display system and can be viewed
again at a later date. Records are stored for up to 10 faults, the older records being viewed by pressing the
button. The displays are numbered from 1 to 10 with fault 1 indicating the most recent record. When each
record is viewed the LED's which were indicating at the time of the fault are re-displayed.
The relay triggers the fault recorder (and waveform storage) when the internal logic detects a fault trip
condition.
Fault records are stored in capacitor backed memory.

7.2 Waveform Records

The waveform record feature stores analogue and digital information for all current inputs, voltage inputs,
status inputs and output relays. Waveform storage is triggered by operation of any internal trip function.
In addition, the waveform records can be triggered remotely via a status input or via the serial
communications interface.
Waveforms are stored in a rolling 'time window'. The memory is configured for a default of 10 x 1s records
but can be set to 5 x 2s, 2 x 5s or 1 x 10s. The pre-trigger can be set in 10% steps over the record length.
Any new record over-writes the oldest when the data memory is full. All records are time and date stamped.
Waveform records are stored in RAM with a capacitor providing back-up during breaks in auxiliary supply.
The waveform records can only be examined once they have been downloaded into a suitable data analysis
package such as Reydisp Evolution.

7.3 Event Records

The event recorder feature allows the time tagging of any change of state of the relay. Each event is logged
with the full date and time and actual event condition every 2.5ms. The following events are logged:-
•
Change of setting (though not the actual setting changes). Also indication of which group of settings
is active.
•
Change of state of Output Relays
©2011 Siemens Protection Devices Limited
7SG164 Ohmega 400 Series Description of Operation
Chapter 1 Page 5 of 12