PR 4131 User Manual page 22

Latch
When the setpoint is exceeded the relay outputs enters an alarm state. The
latch function of the 4131 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 4501, 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 31
and 32.
20 4131V104-UK