Endress+Hauser RMA 422 Mise En Service page 60

Process transmitter
Example: A filling height is monitored for its rate of change. In
menu group
switch on threshold value is set up in
the reset value in
in menu group
In this example the relay is deactivated when the increase in
filling height (MW
unit. The relay is only powered up again when the lowering of
the level has reached a value of 2/time unit..
Operation of the alarm feature
If the parameter in
as a system alarm relay. The relay is only deactivated in a unit
fault condition, this can be:
- Cable open circuit as well as a short circuit on 2 wire
transmitters
- Sensor fault on 2 wire transmitters
(<3.6 mA or >21 mA)
- Certain hardware and software faults
(see fault finding)
Operation of the switch time delay
Measurement value
Relay deactivated (no power), yellow LED off
Using this setting a time delay
SETP
If the measurement value falls below the preset switch
threshold
then the switch delay time counter is reset to zero. The time
counter restarts after a new infringement of the preset switch
threshold
This is also valid for minimum monitoring.
58
LIM
address
RESP
is set to
TRDT
.
-MW
E A
MODE
SETP
DELY
and activating the relay can be installed.
SETP
(without hysteresis) within the time delay
SETP
.
MODE
is set to parameter
SETP
-2
. The time cycle tm is set up
) has exceeded the value of 3/time
ALARM
:
ALARM
is set to , then the relay operates
DELY
:
DELY
between switch threshold
TRD
. The
and has the value
HYST
DELY
3
,