lim_alrm

 Function Block - Detects high and low limits of a signal with hysteresis.

Inputs

Input	Data Type See Data Types.	Range	Unit	Default	Description
EPS	REAL				Value of the hysteresis.
H	REAL				Value of the high limit.
L	REAL				Value of the low limit.
X	REAL				Input signal.

Outputs

Output	Data Type See Data Types.	Range	Unit	Description
Q	BOOL	FALSE, TRUE	N/A	TRUE if the signal exceeds one of the limits. Equals to QH OR QL.
QH	BOOL	FALSE, TRUE	N/A	TRUE if the signal exceeds the high limit.
QL	BOOL	FALSE, TRUE	N/A	TRUE if the signal exceeds the low limit.

FBD Language Example

FFLD Language Example

• In the FFLD Language, the input rung (EN) is used for enabling the block.
  • The output rung is the QH output.
  • The block is not called if EN is FALSE.

IL Language Example

Not available.

ST Language Example

(* MyAlarm is a declared instance of LIM_ALRM function block *)
MyAlarm (H, X, L, EPS);
QH := MyAlarm.QH;
Q := MyAlarm.Q;
QL := MyAlarm.QL;

See Also

• Alarm_A

• Alarm_M