Endress+Hauser RIA 450 Manual De Instrucciones página 53

TRD
Tend monitoring
Measurement principle:
The trend monitoring function is for checking the timed change
of the input signal. The time base tm for the monitoring function
is set up in the menu group PARA section TRDT. The difference
between the start value MW
interval is calculated. If the calculated value is higher than the
SP
value set up in the relay is de-energised. The relay switches
on again once the calculated value is less than the value set up
in RESP. The direction of the signal is set by using the prefix. A
new value is calculated every 0.4 seconds (sliding interval).
Relay
Example: The display shows a filling level which requires
monitoring. In menu group
TRD
. The parameter set for the switch point SP is
set is
reset switch point RESP is set to
in menu group PARA address TRDT.
In this example the relay is de-energised when the level
(MW -MW ) change exceeds the value of 3/time units. The
E A
relay is energised again when the level change is 2/time units.
Fault recognition
If the parameter set in
an alarm relay. In fault condition the relay is de-energised. This
happens with the following faults:
- Cable open circuit and short circuit with 2 wire transmitters
- Sensor fault with 2 wire transmitters (<3.6mA or >21mA)
- Cable open circuit on RTDs or thermocouples
- Various recognisable hardware and software faults
(Please see fault finding).
TRD-
/ :
and the end value MW
A
LIM1
address MODE the parameter
-2
. The time base tm is set up
OC
:
LIM1
MODE is at
of the
E
3
, the
OC
, relay 1 operates as
Process display
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