Autonics TK4M - Loop Break Alarm [PAR4 → AL-1;AL-2 → LBA]

6 Parameter Settings and Functions
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6.4.7 Loop Break Alarm [PAR4 → AL-1/AL-2 → LBA]
 Diagnoses the control loop by monitoring the control subject's temperature changes
and sends out alarms if necessary.
 Heating control: When control output MV is 100% or high limit (H-MV) and PV is not
increased over than LBA detection band (
LBA.B)during LBA monitoring time (LBA.T),
or when control output MV is 0% or low limit (
L-MV) and PV is not decreased below
than LBA detection band (
LBA.B) during LBA monitoring time (LBA.T), alarm output
turns ON.
 Cooling control: When control output MV is 0% or low limit (L-MV) and PV is not
increased over than LBA detection band (
LBA.B) during LBA monitoring time (LBA.T),
or when control output MV is 100% or high limit (
H-MV) and PV is not decreased
below than LBA detection band (
LBA.B) during LBA monitoring time (LBA.T), alarm
output turns ON.
Common Causes of LBA Output On
 Sensor Error (disconnection, short)
 External Controller Error (magnet, auxiliary relay, etc.)
 External Load Error (heater, cooler, etc.)
 Misconnections and disconnections of external network.
 Set alarm output mode(
AL-□
) as loop break alarm (
LBA
) and you
can use loop break alarm.
 LBA operates only when control output MV is low limit (
L-MV
), 0%,
high limit (
H-MV
), or 100%.
 In case of AT (auto-tuning)/manual control/stop control, loop break
alarm (
LBA
) does not operates
 When alarm reset is input, it initializes LBA monitoring start time.
6.4.7.1 LBA Monitoring Time [PAR4 → LBA.T]
You can set the LBA monitoring time to check changes in the control subject's
temperature.
Automatically setting with auto-tunning.
Setting
Group
Parameter Setting Range
Factory
Default
Unit
PAR4
LBA.T
0000
to
9999
0000
Sec