ABB Relion 670 series Engineering Manual page 98

Section 7
Local HMI engineering
92
LED operation mode LatchedReset-S
S1
S2
S3
S4
tMax
tRestart
Auto-
Reset
Man-
Reset
S1LED
S2LED
S3LED
S4LED
Illumination => = Steady
IEC08000400 V1 EN-US
Figure 57: LHMI: LED operation mode LatchedReset-S
The LatchedReset-S mode is designed for multi-signal disturbance monitoring. For
this reason, the General LED indication function block (LEDGEN) has two
parameters: tRestart and tMax. Both are timers used to determine the end of a
disturbance window.
A disturbance window starts when a LED receives a binary On signal. The LED
then enters a steady lit state. At the point where all signals, related to the LEDs in
this particular mode, are Off, the timer tRestart is triggered. This timer is common
for all LEDs and when it elapses, the disturbance window ends.
The second timer, tMax, starts whenever a LED is lit. If there are no activities until
tMax elapses, tRestart is triggered. This means that the disturbance window
eventually ends even if a signal remains On for a long time. See
= Flash
IEC08000400.vsd
1MRK 511 398-UEN C
Figure 57.
670 series 2.2 IEC
Engineering manual