User guide

Publication 900-UM007D-EN-E - January 2011
Parameter Adjustments & Application Considerations 4-49
Parameters Related to Loop Break Alarms
➊ Set NONE as the unit for analog inputs.
• A loop break alarm can be output by setting the Alarm 1 Type to 12
(LBA).
• A setting of 12 (LBA) can be configured for Alarm 2 or 3 but the setting
will be disabled.
• Loop breaks are not detected during SP Ramp operation.
• Loop breaks are not detected during Auto-Tuning, Manual operation, or
while the controller is stopped.
• If the Alarm 1 Latch parameter is configured to ON, the latch will be
effective for the loop break alarm.
Automatically Setting the LBA Detection Time
• The LBA Detection Time is automatically configured by Auto-Tuning.
(However, it is not configured automatically for heating/cooling
control.)
• If the optimum LBA Detection Time is NOT obtained by Auto-Tuning,
configure the LBA Detection Time parameter (Advance Setting
function group).
Table 4.AB
Parameter Name Symbol Sensor Type
Configurable Range
(Units)
Application
Considerations
LBA Detection Time lba
0…9999 (s)
Setting 0 disables the LBA
function.
LBA Level lbal Controllers with
Thermocouple and
Resistance Thermometer
(RTD) inputs
0.1…999.9 (°C/°F) ➊ Default: 8.0 (°C/°F)
Controllers with Analog
Inputs
0.01…99.99 (%FS) Default: 10.00% FS
LBA Band lbab Controllers with
Thermocouple and
Resistance Thermometer
(RTD) inputs
0.0…999.9 (°C/°F) ➊ Default: 3.0 (°C/°F)
Controllers with Analog
Inputs
0.00…99.99 (%FS) Default: 0.20% FS