Siemens 7SG11 Manual page 29

Change of setting (though not the actual setting changes). Also indication of which group of settings is active
Change of state of output relays
Change of state of status inputs
Change of state of any protection characteristic
Trip indication reset
Trip test
Trip supply failure
Circuit Breaker maintenance alarms
Circuit breaker failure
The event storage buffer holds 500 records. When the event buffer is full, then any new record overwrites the
oldest.
Event records are stored in RAM with a capacitor providing back-up during breaks in auxiliary supply.
The event record store can be erased when viewing the "events stored" instrument screen and pressing the
TEST/RESET button.
1.3.6 General
Multiple Settings Groups
Argus relays provide eight alternative settings groups, making it possible to edit one group while the protection
algorithms operate using another 'active' group. The Argus can then be switched from one group of settings to
another to suit alterations in the power system configuration. A change of group can be achieved either locally at
the fascia, remotely via a communications interface command or by energisation of a status input. On models with
a voltage element, this can also be used to change settings group.
For setting group change by status input, the 'Settings Group Select' setting is used to configure any one (or
more) of the status inputs to select a settings group. The selected group is then made active if the status input is
energised and remains active for as long as the input remains energised.
If multiple status inputs are energised, the lower (or lowest) number status input takes precedence. For instance,
if status input 1 activates settings group 5 and status input 3 activates settings group 2, and both status inputs are
energised, the Argus would operate in settings group 5.
Self Monitoring
The Argus incorporates a number of self-monitoring features listed below, each of which initiates a reset
sequence that can be used to generate an alarm output. In addition, the Protection Healthy LED gives visual
indication.
Power supply watchdog
Microprocessor watchdog
Program memory test using CRC
Any failure is detected with sufficient time warning so that the microprocessor can be shut down in a safe and
controlled manner.
Password Feature
The programmable password feature enables the user to enter a 4 character alpha-numeric code. As soon as the
user attempts to change a setting the password is requested before any setting alterations are allowed. Once the
password has been validated, the user is said to be "logged on" and any further changes can be made without re-
entering the password. If no more changes are made within I hour then the user will automatically be "logged out",
re-enabling the password feature. Note that the password validation screen also displays a numerical code. If the
password is lost or forgotten, authorised personnel can communicate this code to Siemens Protection Devices
Limited. and the password can be retrieved. The Argus is supplied with the password set to "NONE" which
means the feature is de-activated.
©2013 Siemens Protection Devices Limited
7SG11 Argus User Manual
P20006 Page 11 of 37