Campbell Scientific LR4 Four Channel Latching Relay Module - Manual (Page 9)

LR4 Four Channel Latching Relay Module
FIGURE 3. Form A - State = 0
FIGURE 4. Form C - State = 1
FIGURE 5. Form C - State = 0
4.2 Relay Contact Life
The expected life of the relays under no load conditions is 50 million
operations. Under load, the life expectancy is reduced to 100,000 operations.
Inductive loads can further reduce the life expectancy of the relay contact.
Proper signal conditioning (clamping diodes) should be considered for
inductive loads.
5. Manual Toggle Control
There is one Manual Toggle push button for each relay. The state of a relay
can be changed by pressing the corresponding button and holding it in place for
2 seconds. If a relay is in the 1 state when a button is pressed, the
corresponding LED will turn on; two seconds later the user will see the LED
go off once the relay has changed to the 0 state. In a quiet environment, a click
can also be heard when the relay changes state. Likewise, if an LED is in the 0
state, the corresponding LED will be off when a button is pressed and then turn
on once the relay has gone to the 1 state. The button must be released and
depressed again to change the state again.
To conserve power, the indicating LEDs flash briefly once every 5 seconds. A
brief momentary push (less than 1 second) of any button will cause the control
module to turn on any LED whose relay is in the 1 state for several seconds.
Only one button should be pressed at a time. Once a relay is controlled
manually, the relay remains in that state until a command or button is used to
change the relay state.
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