Operating Instructions

Table Of Contents
A.9 Fail-safe Mode
A.9.1 Fail-safe Mode
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.
A.9.2 Fail-safe Timer
Fail-safe Timer determines the time to elapse after the last valid reading before a Failsafe state
is activated. Fail-safe Material Level determines the level to be reported when the Fail-safe
timer expires. Upon receiving a reliable echo, the loss of echo condition is aborted, the Service
Required icon and error message are cleared, and the reading and mA output return to the
current level.
A.9.3 Fail-safe Material Level
When the Fail-safe Timer 2.4.1. (Page 94) expires, the material level to be reported is
determined by
Fail-safe Material Level
HI Use Maximum mA Limit as material level
LO Use Minimum mA Limit as material level
HOLD Level remains at last reading
VALUE User-selected value as defined in Fail-safe Level
A.9.4 Fail-safe Level
When Fail-safe Material level is set to Value, the Fail-safe Level defines a user-defined level to
report when the Fail-safe timer expires.
Fail-safe Level
Values 3.6 to 22.6 mA
Appendix A: Technical reference
A.9 Fail-safe Mode
SITRANS LR260 with mA/HART
158 Operating Instructions, 11/2019, A5E32337683-AD