User's Manual

Page 122 SITRANS LR560 (PROFIBUS PA) – OPERATING INSTRUCTIONS 7ML19985LT01
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D: Technical Reference
Fail-safe Behavior
The purpose of the Fail-safe setting is to put the process into a safe mode of operation in
the event of a fault or failure. The value to be reported in the event of a fault is selected so
that a loss of power or loss of signal triggers the same response as an unsafe level.
Fail-safe mode may be triggered by a loss of echo, a bad configuration, or certain device
faults. You can select one of three possible values to be reported when a Fail-safe mode
is activated.
Mode (2.5.9.1.)
Mode determines the material level to be reported when LOE Timer (2.3.3.) expires.
Value (2.5.9.2.)
Value defines the material level to be reported if the option Use substitute value is
selected in Mode (2.5.9.1.).
The two Analog Input Function blocks are set separately.
To set a user-defined value
• Navigate to the Level Meter > Setup > desired Analog Input (1 or 2).
•Set Mode (2.5.9.1.) to Use substitute value.
•Go to Value (2.5.9.2.) and enter the desired value.
Mode (2.5.9.1.)
SUB VALUE Use substitute value. Value (2.5.9.2.) used as output value.
LAST VALUE * Last value (Store last valid output value).
USE BAD VALUE Use bad value (Calculated output value is incorrect).