Latch
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Latch
When the setpoint is exceeded the relay outputs enters an alarm state. The latch function of the DRST-UR will
hold the relays in this state until the function is deactivated manually. The latch function can be applied
when the relay function setpoint or window is selected.
The latch function can be selected separately for each relay output. If the configuration is copied from one
device to another by way of the DRSL-DISPLAY, the latch function must be reconfigured.
The latch function activates and holds the relays when the input signal rises above or falls below the selected
setpoints and the relay action has been selected as increasing or decreasing.
The window function is selected by choosing ”window” in the menu and defining a high and a low setpoint.
It can be selected for each relay contact whether the contact is open or closed inside the window. This
selection is made in the menu R1.cont and R2.cont.
The setpoint function is selected by choosing ”setpoint” in the menu and entering the desired limit. The
device then works as a single limit switch.
An activated relay means that the contact is closed if the contact function ”normally open” is selected, and the
contact is open if the contact function ”normally closed” is selected.
The delay time for activation and deactivation can be set independently of each other in the menus ON.DEL
and OFF DEL respectively.
If the relay function ”Error” is active, the relay will latch when a sensor error occurs and will not be
deactivated automatically when the sensor error is rectified.
The relay can only be deactivated by an operator and only when the normal conditions for deactivation are
met. If the input signal still has a value that will activate the relay, the relay will latch again.
See the graphic depiction of the setpoint and window functions on pages 34 and 35.
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