HYSTER (hysteresis)

Boolean hysteresis on the difference of reals. Compares the current value of an input with the high limit established by adding the historical amount of lag as measured by hysteresis to the expected value for an input and assessing whether the current value exceeds that limit.
Languages supported: Function block diagram, ladder diagram, structured text.
This instruction applies to the Micro810, L20E, L50E, and L70E controllers.
HYSTER
HYSTER
HYSTER parameters
Parameter
Parameter Type
Data Type
Description
EN
Input
BOOL
Instruction block enable.
  • TRUE: Execute the instruction block.
  • FALSE: Do not execute the instruction block.
Applies only to ladder diagram programs.
XIN1
Input
REAL
Any real value.
XIN2
Input
REAL
To test if the input value XIN1 has exceeded the high limit defined for this input XIN2 + EPS.
EPS
Input
REAL
Hysteresis value (must be greater than zero).
ENO
Output
BOOL
Enable output.
Applies only to ladder diagram programs.
Q
Output
BOOL
The result of the HYSTER instruction.
  • TRUE: The input exceeded the upper limit but is not below the lower limit.
  • FALSE: The input did not exceed the upper limit.

HYSTER timing diagram example

In the following diagram, HYSTER is used to assess the performance lag due to motor friction over a five-second time period. The instruction is run every 10 milliseconds. During the startup phase, the motor was operating less efficiently.
HYSTER timing diagram example
HYSTER timing diagram example

HYSTER examples

HYSTER function block diagram example
HYSTER function block diagram example
HYSTER ladder diagram example
HYSTER ladder diagram example
HYSTER structured text example
HYSTER structured text example
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