If the signal is still
ON
when a reset LED is done, the LED will illuminated again.
This occurs when the application configuration accesses the signal again in the next
cycle after reset. The thin dashed lines in
shows the internal state of the
LED following the signal and reset, when no higher prior signal is given.
The LED illuminates always in steady mode.
LED operation mode LatchedReset-S
IEC08000400.vsd
= Steady
= Flash
Illumination =>
Man-
Reset
S1
S2
S3
S4
tMax
tRestart
S1LED
S2LED
S3LED
S4LED
Auto-
Reset
IEC08000400 V1 EN
Figure 44:
LHMI: LED operation mode LatchedReset-S
This mode is useful to monitor signals that are involved in case of a disturbance,
see
. The signal state after the disturbance allows a fast overview about
the disturbance. To get always the situation of the last occurred disturbance, the
LEDs are reset after a predefined time (tReset). So this is the longest time a
disturbance can be monitored by the LED situation.
In case a second disturbance occurs before the tReset time has elapsed, see
, the signals that are still ON at the end of tReset will return to ON with the next
application configuration cycle after tReset. To clear these LEDs, a second timer
tMax is used. TMax is started when the first signal of the disturbance changes to
ON. tMax is stopped, when tReset could clear all LEDs.
A disturbance runs for a maximum of some seconds, while tReset can be in the
range of 60 to 90 seconds.
The timer tReset and tMax are configured in PST as part of the function block
LEDGEN
Section 6
1MRK511240-UEN B
Local HMI engineering
60
670 series
Engineering Manual
