Omron E5CN User Manual page 117

Loop Break Alarm
Parameters Related to Loop Break Alarms
Parameter name Symbol
lba
LBA detection time
lbal
LBA level
lbab
LBA band
Note
Automatically Setting
the LBA Detection
Time
Determining the LBA
Detection Time
1,2,3...
• Detection in not possible if a fault occurs that causes an increase in tem-
perature while control is being applied to increase the temperature (e.g.,
an SSR short-circuit fault).
• Detection in not possible if a fault occurs that causes a decrease in tem-
perature while control is being applied to decrease the temperature (e.g.,
a heater burnout fault).
Setting range
0 to 9999 (s)
Controllers with Thermo-
couple/Resistance Ther-
mometer Multi-inputs
Controllers with Analog
Inputs
Controllers with Thermo-
couple/Resistance Ther-
mometer Multi-inputs
Controllers with Analog
Inputs
Set "none" as the unit for analog inputs.
• A loop break alarm can be output by setting the alarm 1 type to 12 (LBA).
• The ALM1 indicator will light when a loop break is detected.
• Loop breaks are not detected during SP ramp operation.
• Loop breaks are not detected during auto-tuning, manual operation, or
while stopped.
• If the alarm 1 latch is set to ON, the latch will be effective for the loop
break alarm.
• The LBA detection time is automatically set by auto-tuning.
(It is not set automatically, however, for heating/cooling control.)
• If the optimum LBA detection time is not obtained by auto-tuning, set the
"LBA detection time" parameter (advance function setting level).
• To manually set the LBA detection time, set the "LBA detection time"
parameter to twice the LBA reference time given below.
1. Set the output to the maximum value.
2. Measure the time required for the width of change in the input to reach the
LBA band.
Measurement time
Tm
Temperature
LBA detection time = Tm
0.1 to 999.9 ( C/ F) (See
note.)
0.01 to 99.99 (%FS)
0.0 to 999.9 ( C/ F) (See
note.)
0.00 to 99.99 (%FS)
MV = 100%
2
Section 4-12
Remarks
Setting 0 disables the LBA
function.
Default: 8.0 ( C/ F)
Default: 10.00% FS
Default: 3.0 ( C/ F)
Default: 0.20% FS
PV
LBA band
Time
95