Supervision; Ddb: ‘Function Key’ (See P44X/En Pl); Ddb: ‘Fnkey Led 1 Red’; Ddb ‘Led 1 Red’ - GE MiCOM P40 Agile Technical Manual

P44x/EN AP/Hb6
(AP) 5-136
specifically provided to allow the locking of a function key therefore preventing further
activation of the key on consequent key presses. This allows function keys that are set to
'Toggled' mode and their DDB signal active 'high', to be locked in their active state therefore
preventing any further key presses from deactivating the associated function. Locking a
function key that is set to the "Normal" mode causes the associated DDB signals to be
permanently off. This safety feature prevents any inadvertent function key presses from
activating or deactivating critical relay functions. The "Fn. Key Labels" cell makes it possible
to change the text associated with each individual function key. This text will be displayed
when a function key is accessed in the function key menu, or it can be displayed in the PSL.
The status of the function keys is stored in battery backed memory. In the event that the
auxiliary supply is interrupted the status of all the function keys will be recorded. Following
the restoration of the auxiliary supply the status of the function keys, prior to supply failure,
will be reinstated. If the battery is missing or flat the function key DDB signals will set to logic
0 once the auxiliary supply is restored. The relay will only recognise a single function key
press at a time and that a minimum key press duration of approximately 200msec. is
required before the key press is recognised in PSL. This deglitching feature avoids
accidental double presses.
DDB: 'Function Key' (see P44x/EN PL)
The activation of the function key will drive an associated DDB signal. The DDB signal will
remain active depending on the programmed setting i.e. toggled or normal. Toggled mode
means the DDB signal will remain latched or unlatched on key press and normal means the
DDB will only be active for the duration of the key press.
DDB: 'FnKey LED 1 Red'
Ten programmable tri-colour LEDs associated with each function key are used to indicate
the status of the associated pushbutton's function. Each LED can be programmed to indicate
red, yellow or green as required. The green LED is configured by driving the green DDB
input. The red LED is configured by driving the red DDB input. The yellow LED is configured
by driving the red and green DDB inputs simultaneously. When the LED is activated the
associated DDB signal will be asserted. For example, if FnKey Led 1 Red is activated, DDB
will be asserted.
DDB 'FnKey LED 1 Grn'
The same explanation as for Fnkey 1 Red applies.
DDB 'LED 1 Red'
Eight programmable tri-colour LEDs that can be programmed to indicate red, yellow or green
as required. The green LED is configured by driving the green DDB input. The red LED is
configured by driving the red DDB input. The yellow LED is configured by driving the red and
green DDB inputs simultaneously. When the LED is activated the associated DDB signal will
be asserted. For example, if Led 1 Red is activated, DDB #640 will be asserted.
DDB 'LED 1 Grn'
The same explanation as for LED 1 Red applies.
5.8

Supervision

The "Supervision" menu contains 3 sections:
• the Voltage Transformer Supervision (VTS) section, for analog ac voltage inputs
failures supervision,
• the Current Transformer Supervision (CTS) section, for ac phase current inputs
failures supervision,
• the Capacitive Voltage Transformer Supervision (CVT) section, for voltage dividers
capacitors supervision.
Application Notes
MiCOM P40 Agile P442, P444