lim_alrm

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Function Block A function block groups an algorithm and a set of private data. It has inputs and outputs. - Detects high and low limits of a signal with hysteresis.

Inputs

Input	Data Type	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	Description
Q	BOOL	TRUE if the signal exceeds one of the limits. Equals to QH OR QL.
QH	BOOL	TRUE if the signal exceeds the high limit.
QL	BOOL	TRUE if the signal exceeds the low limit.

Output

Data Type

Range

Unit

Description

BOOL

TRUE if the signal exceeds one of the limits.

Equals to QH OR QL.

BOOL

TRUE if the signal exceeds the high limit.

BOOL

TRUE if the signal exceeds the low limit.

Remarks

None

FBD Language Example

FFLD Language Example

In the FFLD Language, the input rung (EN) is used for enabling Enable signal for the drive, Hardware-Enable with 24V signal to X8, Software-Enable command by setup Software, fieldbus or permanently set. Both are required for enabling the drive. the block.
- The output rung is the QH output.
- The block is not called if EN is FALSE.

IL Language Example

(* MyAlarm is a declared instance of LIM_ALRM function A function calculates a result according to the current value of its inputs. 
A function has no internal data and is not linked to declared instances. block *)
Op1: CAL MyAlarm (H, X, L, EPS)
     FFLD  MyAlarm.QH
     ST  QH
     FFLD  MyAlarm.Q
     ST  Q
     FFLD  MyAlarm.QL
     ST  QL

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;