Endress+Hauser RIA 450 - Unit Function; Relay Menu Group

6. Unit function
6.1 Relay menu group
The following is a description of the settings for the four alarm
relays. Each individual relay must be set up in the four menu
groups
LIM1 to LIM4.
It is important that the relays are deactivated when the alarm
set point is active. The four menu groups
LIM1 to LIM4 are only
available in units with the RELAY option.
Relay switched off
OFF
The selected relays together with the set point arrows are
switched off. This means the relays are no longer functional.
Alarm function on set point infringement
MIN / MIN-
(Minimum safety) and MAX / MAX- (Maximum safety):
Here the safety function of the relay is set up i.e. if the relay is
to deactivate on undercutting or exceeding the preset
measured set point value.
Example: In Menu group LIM1 the parameter
MAX is set up in
MODE, the set point
SP is set to 50, the hysteresis HYST is set to
10. In this case relay 1 will deactivate at 50%. With a 40%
signal the relay will switch on again.
Measured value
Measured value
MIN
MAX
SP
SP
HYST.
HYST.
¬ Relay de-energised
Process display
50