Flowline LU78 EchoSwitch - Manual (Page 18)

18 of 34 MN300282 Rev A
CONFIGURATION (cont.) Step Five
How to set Relay Fail‐Safe / LOST: In the event the sensor does not receive an echo, the Fail‐Safe Output or
LOST setting can be set to turn each relay ON, OFF or HOLD (to last state) to achieve the desired fail‐safe
condition. During fail‐safe, the display will read LOST.
1. In TOP‐LEVEL MENU mode, select SAFE.
2. Select R1 (Relay 1), R2 (Relay 2) or R2 (Relay 3).
3. Select ON, OFF, or HOLD.
4. Select EXIT to return to TOP‐LEVEL MENU.
Power Outage: If power to the EchoSwitch® is
removed (intentionally or accidentally), the relays
will return to the normal state. Thus, in Relay 1, NC
terminal will be closed and NO terminal will be open.
Also, the NO terminals in relays 2 and 3 will also be
open. Make sure that the de‐energized state is the
safe state in your system design. The EchoSwitch®
does use non‐volatile memory so any power loss will
not affect the settings or configuration of the sensor.
How to select Fail‐Safe Current Output / LOST: In the event the sensor does not receive an echo, the Fail‐Safe
Current Output or LOST setting can be set to output a current of 4mA, 21mA or Hold (last known value).
During fail‐safe, the display will read LOST.
1. In TOP‐LEVEL MENU mode, select SAFE.
2. Select OUTPUT.
3. Select 4mA, 21mA, or HOLD.
4. Select EXIT to return to TOP‐LEVEL MENU.