Autonics TK Series User Manual

6 Parameter Settings and Functions
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6.4.7 Loop break alarm(LBA) [PAR4 → AL-1/AL-2/AL-3 → 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 [LBaB] during LBA monitoring time [LBaT], or
when control output MV is 0% or low limit [L-MV] and PV is not decreased below than LBA
detection band [LBaB] during LBA monitoring time [LBaT], 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 [LBaB] during LBA monitoring time [LBaT], or when control
output MV is 100% or high limit [H-MV] and PV is not decreased below than LBA detection
band [LBaB] during LBA monitoring time [LBaT], 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.
If it is not as sensor break/HHHH/LLLL, during auto-tuning/manual control/control STOP/ramp
function operation, loop break alarm does not operate.
Type
LBA
monitoring
time
Alarm output
Standard alarm Alarm latch
Initializing Alarm, changing control
output operation mode, setting LBA
monitoring time/band as 0
Initialize
OFF OFF
Changing input correction value, set
value
Maintains the
present alarm
Maintains the
present alarm
Changing MV, stopping control, running
auto-tuning
OFF
Maintains the
present alarm
Occurring sensor break alarm, HHHH,
LLLL
ON ON
Set alarm operation[AL-□] as loop break alarm [LBA] and you can use loop break alarm.
When executing auto-tuning, LBA detection band [LBaB] and LBA monitoring time[LBaT] is
automatically set based on auto-tuning value.
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.

Autonics TK Series Specifications

General

Brand	Autonics
Model	TK Series
Category	Temperature Controller
Language	English