Rockwell Automation DeviceLogix System User Manual - Manual (Page 24)

24 Publication RA-UM003B-EN-P - February 2010
Chapter 2 Navigate the Function Block Editor Interface
Alarm
The Alarm function block initiates an alert based on the comparison
between the input value and the threshold. The output of the
DeviceLogix Alarm function block contains these alerts.
• High-High alarm
• High alarm
• Low alarm
• Low-Low alarm
The details of the Alarm function block are outlined in the table.
The valid parameter range is shown below:
Condition Output Fault State
INPUT > HHLimit (including the case when
HLimit==HHLimit) 0x000C 0
HLimit < INPUT < HHLimit 0x0004 0
LLimit < INPUT < HLimit 0x0000 0
LLLimit < INPUT < LLimit 0x0002 0
INPUT < LLLimit (including the case when
LLimit==LLLimit) 0x0003 0
INPUT is NAN* Keep the output
unchanged 2
INPUT is positive infinity 0x000C 2
INPUT is negative infinity 0x0003 2
Input value from binding source is out of the
object's range Keep the output
unchanged 1
*The condition is only possible when Operation Data Type is REAL.
Parameters Data Range
HHLimit -2147483648 ~ 2147483647 (DINT)
-3.402823466e+38F ~ 3.402823466e+38F (REAL)
HLimit -2147483648 ~ 2147483647 (DINT)
-3.402823466e+38F ~ 3.402823466e+38F (REAL)
LLimit -2147483648 ~ 2147483647 (DINT)
-3.402823466e+38F ~ 3.402823466e+38F (REAL)
LLLimit -2147483648 ~ 2147483647 (DINT)
-3.402823466e+38F ~ 3.402823466e+38F (REAL)
Note: HHLimit >=HLimit >=LLimit >=LLimit