Out3P (FB)¶

FUNCTION_BLOCK Out3P

Short Description¶

Conversion of an analog value (e. g. P-controller) into output signals for a 3-point actuator (pulse width modulation).

In addition, a reference position (limit switch) of the actuator can be detected.

Portrayal¶

Interfaces¶

Inputs¶

Name
Datatype

Range

Init-Value

Function

xEn BOOL
Enable Functionblock

rIn REAL
Inputsignal

xRefPos BOOL
Digital input to detect the reference position (limit Switch).

Outputs¶

Name
Datatype

Range

Init-Value

Function

xOutOpen BOOL
Output variable Plus/More for the drive

xOutClose BOOL
Output variable Minus/less for the drive

rPos REAL 0.0 ... 100.0
Analog signal for the current position

Setpoints / Parameters¶

Name
Datatype

Range

Init-Value

Function

iRefPosition INT 0 - 100 0%
Reference position of the drive

tImpulsClose TIME 1s
Duration of a pulse at the output Minus/less than

tImpulsOpen TIME 1s
Duration of a pulse at output Plus/More

rMinLimit REAL -100.0
Integral value for pulse triggering at the output minus/less than

rMaxLimit REAL 100.0
Integral value for pulse triggering at output Plus/More

rDuration TIME 120s
Operating time of the drive

tIntegration TIME 100ms
Duration between two integration processes

Functional Description¶

General¶

This function block is used to convert the analog signal rIn into the corresponding output signals xOutOpen and xOutClose in the form of a pulse width modulation.
The pulse length is always constant (tImpulsClose or tImpulsOpen) while the pause between two pulses is different.
With a current input signal rIn of 0.0, no output pulses are generated.
If the current input signal is in the positive range (0.0 - +100.0), pulses are only generated at the xOutOpen output.
If the current input signal is in the negative range (0.0 - -100.0), only xOutClose pulses are generated at the output.
The function block is enabled/disabled via the digital input xEn.
Each rising edge at the digital input xRefPos (i. e. the drive is currently in its reference position) causes the analog output signal rPos to be reset to the setpoint / parameter iRefPosition.

Enable input xEn¶

If the enable input is not active (xEn = FALSE) both outputs xOutOpen and xOutClose are reset. In addition, the integral is set to 0 and the digital signal for detecting the reference position xRefPos has no function.

With each falling edge at the enable input, the output signal xOutClose is permanently activated for a duration of time of rDuration + 10s and at the same time the output signal xOutOpen is deactivated (= forced movement of the drive in rest position).

Reference position¶

The digital input xRefPos allows a new adjustment of the position display rPos to a predefined value iRefPosition (0% = rest position - 100% = maximum position).

Each rising edge at the digital input triggers a new adjustment.

Signal generation¶

The analog input signal rIn (control deviation of a control process, signal symmetrical to the zero point) is integrated in the tIntegration interval over time.

This means that after each tIntegration integration interval ,the product of rIn and the tIntegration is formed and added to the current contents of the integration memory. A step function is thus created.

Example

rIn* = 100K, tIntegration = 100ms, old value of the integration memory = 500Ks, new value (after 100ms) = 510Ks.

If the integration value exceeds the limit value rMaxLimit, a pulse of the length tImpulsOpen is generated on the output signal xOutOpen.
If the integration value falls below the limit value rMinLimit, a pulse of the length tImpulsClose is generated on the output signal xOutClose.
After each pulse generation, the integration value is reset to 0.
The limit value rMaxLimit may only take values > 0.0, the limit value rMinLimit may only take values < 0.0.

Examples with different parameters

tIntegration = 100ms, rMaxLimit = 100.0, rMinLimit = -100.0: With an input signal rIn of +5.0 at the output xOutOpen, a pulse with the length of 1s is generated every 4s.
tIntegration = 100ms, rMaxLimit = 100.0, rMinLimit = -100.0: With an input signal rIn of -5.0 at the output xOutClose, a pulse with the length of 1s is generated every 4s.

tIntegration = 200ms, rMaxLimit = 100.0, rMinLimit = -100.0: With an input signal rIn of +5.0 at the output xOutOpen, a pulse with the length of 1s is generated every 2s.
tIntegration** = 200ms, rMaxLimit = 100.0, rMinLimit = -100.0: Bei einem Eingangssignal rIn von -5.0 am Ausgang xOutClose wird alle 2s ein Impuls mit der Länge 1s erzeugt.

tIntegration = 100ms, rMaxLimit = 200.0, rMinLimit = -100.0: With an input signal rIn of +5.0 at the output xOutOpen, a pulse with the length of 1s is generated every 8s.
tIntegration = 100ms, rMaxLimit = 200.0, rMinLimit = -100.0: With an input signal rIn of -5.0 at the output xOutClose, a pulse with the length of 1s is generated every 8s.

Position display rPos¶

It is used to display the current position of the 3-point drive in the range 0 - 100% and is calculated internally (0% = rest position, 100% = maximum position).
To avoid deviations between the calculated and the actual position, it is recommended that the readjustment of the position indicator be triggered regularly.
The position display is independent of signal generation, i. e. if the position display reaches an end position (0% or 100%), signals are still generated at the
xOutOpen or xOutClose outputs.

Visualization¶

Information¶

Element
Authors

Date
Version
Note

Function
Adam Bartod 11.2016 1.0
Init-Version

Programming
Adam Bartod 02.2017 1.0
Init-Version

Test Jochen Reu / 02.2017 1.0
Init-Version

Documentation
Jochen Reu 10.2017 1.0
Init-Version

Codesys¶

InOut:

Scope	Name	Type	Initial	Comment
Input	xEn	BOOL		Enable Functionblock
	rIn	REAL		Inputsignal
	xRefPos	BOOL		Digital signal for detecting the reference position (limit switch)
	iRefPosition	INT	0	Reference position of the drive
	tImpulsClose	TIME	TIME#1s0ms	Duration of a pulse at the output Minus/less than
	tImpulsOpen	TIME	TIME#1s0ms	Duration of a pulse at output Plus/More
	rMinLimit	REAL	-100.0	Integral value for pulse triggering at the output minus/less than
	rMaxLimit	REAL	100.0	Integral value for pulse triggering at output Plus/More
	tDuration	TIME	TIME#2m0s0ms	Operating time of the drive
	tIntegration	TIME	TIME#100ms	Duration between two integration processes
Output	xOutOpen	BOOL		Output variable Plus/More for the drive
	xOutClose	BOOL		Output variable Minus/less for the drive
	rPos	REAL		Analog signal for the current position