Autonics TM Series User Manual

6 Parameter Settings and Functions
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6.4.8 Loop break alarm(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 (MV high limit) and PV is not
increased over than LBA detection band (LBA Band) during LBA monitoring time (LBA
Time), or when control output MV is 0% or low limit (MV low limit) and PV is not decreased
below than LBA detection band (LBA Band) during LBA monitoring time (LBA Time), alarm
output turns ON.
 Cooling control: When control output MV is 0% or low limit (MV low limit) and PV is not
increased over than LBA detection band (LBA Band) during LBA monitoring time (LBA
Time), or when control output MV is 100% or high limit (MV high limit) and PV is not
decreased below than LBA detection band (LBA Band) during LBA monitoring time (LBA
Time), 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 output operation mode (Alarm Mode) as loop break alarm (LBA) and you can use loop
break alarm.
When executing auto-tuning, LBA detection band (LBA Band) and LBA monitoring time(LBA
Time) 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 TM Series Specifications

General

Brand	Autonics
Model	TM Series
Category	Temperature Controller
Language	English