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

Parameter | Parameter Type | Data Type | Description |
---|---|---|---|
EN | Input | BOOL | Instruction block enable.
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.
|
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 examples
HYSTER function block diagram example

HYSTER ladder diagram example

HYSTER structured text example

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