HYSTERPLCopen motion icon

Function BlockClosed A function block groups an algorithm and a set of private data. It has inputs and outputs. - Hysteresis detection.

Inputs

XIN1 : REAL  First input signal
XIN2 : REAL  Second input signal
EPS : REAL   Hysterisis

Outputs

Q : BOOL     Detected hysteresis: TRUE if XIN1 becomes greater than XIN2+EPS and is not yet below XIN2-EPS

Remarks

The hysteresis is detected on the difference of XIN1 and XIN2 signals. In FFLD language, the input rung (EN) is used for enabling the block. The output rung is the Q output.

ST Language

(* MyHyst is a declared instance of HYSTER function block *)
MyHyst (XIN1, XIN2, EPS);
Q := MyHyst.Q;

FBD Language

HysterFbd.gif (1415 octets)

FFLD Language

(* The block is not called if EN is FALSE *)
HysterLd.gif (1611 octets)

IL Language:

(* MyHyst is a declared instance of HYSTER function block *)
Op1: CAL MyHyst (XIN1, XIN2, EPS)
FFLD 
MyHyst.Q
STClosed "Structured text" A high-level language that is block structured and syntactically resembles Pascal  Q

See also

AVERAGE   INTEGRAL   DERIVATE   LIM_ALRM   STACKINT