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2 Functions
Figure 2-110
Moreover, the device has several event buffers for operational indications, fault indi-
cations, switching statistics, etc., which are protected against loss of auxiliary supply
by means of a backup battery. These indications can be displayed on the LCD at any
time by selection using the keypad or transferred to a personal computer via the serial
service or operator interface. Reading out indications during operation is described in
detail in the SIPROTEC 4 System Description.
After a fault on the system, for example, important information about the progression
of the fault can be retrieved, such as the pickup of a protective element or the initiation
of a trip signal. The start of the fault is time stamped with the absolute time of the in-
ternal system clock. The progress of the fault is output with a relative time referred to
the instant of fault detection, so that the duration of a fault until tripping and up to reset
of the trip command can be ascertained. The resolution of the time information is 1 ms.
With a PC and the DIGSI protection data processing software it is also possible to re-
trieve and display the events with the convenience of visualisation on a monitor and a
menu-guided dialog. The data may either be printed or stored for evaluation at a later
time and place.
A system fault starts with the detection of the fault by the fault detection of any protec-
tion function and ends with the reset of the fault detection of the last protection function
or after the expiry of the auto-reclose reclaim time, so that several unsuccessful
reclose cycles are also stored cohesively. Accordingly a system fault may contain
several individual fault events (from fault detection up to reset of fault detection).
Information to a
If the device has a serial system interface, stored information may additionally be
Control Centre
transferred via this interface to a centralized control and storage device. Several com-
munication protocols are available for the transfer of this information.
You may test whether the indications are transmitted correctly with DIGSI.
Also the information transmitted to the control centre can be influenced during opera-
tion or tests. The IEC 60870-5-103 protocol allows to identify all indications and mea-
sured values transferred to the central control system with an added indication „test
mode" while the device is being tested on site (test mode). This identification prevents
the indications from being incorrectly interpreted as resulting from an actual power
system disturbance or event. Alternatively, you may disable the transmission of indi-
cations to the system interface during tests („Transmission Block").
To influence information at the system interface during test mode („test mode" and
„transmission block"), a CFC logic is required. Default settings already include this
logic (see Appendix).
The SIPROTEC 4 System Description describes in detail how to activate and deacti-
vate test mode and blocked data transmission.
244
Operational measured values in the default display
7SD610 Manual
C53000-G1176-C145-4
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