Loop Error Indicators; Table 9-3 Abnormal Loop Conditions And Indicators - Honeywell VRX180 User Manual

Diagnostic and error messages

9.2 Loop Error Indicators

When a loop's PV, SP2, or other parameter fails, the loop switches to its default/failsafe condition,
indicated by certain display symbols flashing. To return the loop to its desired condition, correct the
failure. Then, if the loop's LATCHING is NO, the loop will return to normal automatically. If LATCHING
is YES, also perform the action needed to return the loop to normal.
Desired Condition Abnormal Condition
Auto & SP2 SP2 Failure
Manual & SP2 SP2 Failure
Auto & SP2 SP2 & PV Failure
Manual & SP2 SP2 & PV Failure
Auto & SP1/SP2 PV Failure or
Force Remote Manual
Failure or
Output Tracking
Failure or
Feedforward Failure
Manual & SP1/SP2 PV Failure
Auto & SP1/SP2 See below***
Auto & SP1/SP2 Force Remote Manual
*Due to the abnormal condition the loop cannot be in Auto and therefore is in a temporary mode which forces
the output as indicated.
**If loop feedback is not connected to an AO, or if loop type is ON/OFF, then MAN will be steady, not flashing.
***Status from a downstream function block indicates that there is no path to final output element. For
example, the secondary control loop of cascade configuration was changed to manual mode.
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Table 9-3 Abnormal Loop Conditions And Indicators

Video Recorder – User Manual
Default condition
(Failsafe)
Working SP=SP1
Working SP=SP1
Working SP=SP1
Mode = Suspend Auto*
Output = Failsafe
Working SP = SP1
Mode = Manual
Output = Last value
Mode = Suspend Auto*
Output = Failsafe
Mode = Manual
Output = Last Value
Mode = Suspend Auto*
Output = Back Calc. Value
Mode = Suspend Auto*
Output = Tracking value
Flashing Action needed
symbols
(if LATCHING = YES)
SP2 Select SP1 then SP2
SP2 Select SP1 then SP2
SP2 Select SP1 then SP2
AUTO Select Manual then
MAN**
Auto
PV
SP2 Select SP1 then SP2
PV
AUTO Select Manual then
MAN** Auto
PV
PV None required
AUTO None required
MAN
AUTO None required