Supported platforms: CODESYS 2.3, CODESYS 3.5

 

PVC_CurrentValvePair (FB)

Description

PVC_CurrentValvePair function block controls a current controlled proportional pair in products that have a controller built in at firmware, such as Epec 5050.

 

The function block calls PVC_Attenuation FB and one of the ramp FBs according to the user’s selection.

 

The FB uses PVC_To_CurrentReq function to scale the control signal to current requests.

 

The FB checks it’s own parameters to ensure their valid values. In case of an incorrect value in any of the parameters, o_ParameterError output is activated.

 

A value of  -32768 in i_ControlValue will be limited (overwritten) internally to -32767.

In case of a parameter error or i_Enable is inactive, current request outputs are reset.  

 

With i_EnableCounterControl input, the user can enable a counter control feature. The counter control feature allows both valves to be controlled simultaneously.

 

If i_Enable is inactive or in case of a parameter error or AI voltage error, the current request outputs are set to zero.

 

Limitations

Use with hardware that has a built-in current controller (i.e. mA value is written to output) or with PVC_AdaptiveController.

 

i_Control must be 0 on the rising edge of i_Enable status. Otherwise control is not enabled.

 

When the linear ramp type is selected, the ramp speed changes when the current parameters are changed.

 

Inputs

Input variable name

Data type

Range

Description

i_Enable

BOOL

FALSE/TRUE

Enables controlling of the current request outputs.

i_Control

INT

-32767..32767

Control signal from e.g. joystick

i_PosDirMaxCurrent

UINT

1..2500 mA

Maximum current for valve that is controlled with positive control signal

i_PosDirMinCurrent

UINT

1..2500 mA

Minimum current for valve that is controlled with positive control signal

i_NegDirMinCurrent

UINT

1..2500 mA

Minimum current for valve that is controlled with negative control signal

i_NegDirMaxCurrent

UINT

1..2500 mA

Maximum current for valve that is controlled with negative control signal.

i_RampType

BYTE

0..G_RampTypeMax

Defines which one of the available ramp functions is used.

i_PosDirAscendRamp

UINT

Depends on selected ramp type

Ascending speed for valve that is controlled with positive control signal, range and unit depends on selected ramp type.

i_PosDirDescendRamp

UINT

Depends on selected ramp type

Descending speed for valve that is controlled with positive control signal, range and unit depends on selected ramp type.

i_NegDirAscendRamp

UINT

Depends on selected ramp type

Ascending speed for valve that is controlled with negative control signal, range and unit depends on selected ramp type.

i_NegDirDescendRamp

UINT

Depends on selected ramp type

Descending speed for valve that is controlled with negative control signal, range and unit depends on selected ramp type.

i_PosDirAttenuationOn

BOOL

FALSE/TRUE

If input is true, controlling of positive direction valve is limited to given percentage of max control.

i_NegDirAttenuationOn

BOOL

FALSE/TRUE

If input is true, controlling of negative direction valve is limited to given percentage of max control.

i_PosDirAttenuationAmount

BYTE

0..100%

Amount of attenuation for positive direction valve.

i_NegDirAttenuationAmount

BYTE

0..100%

Amount of attenuation for negative direction valve.

i_EnableCounterControl

BOOL

FALSE/TRUE

Both valves can be controlled at the same time.

Outputs

CODESYS 2.3CODESYS 2.3

Output variable name

Data type

Range

Description

o_PosDirCurrentRequest

UINT

0..2500 mA

Current request for valve controller that is controlled with positive control signal.

o_NegDirCurrentRequest

UINT

0..2500 mA

Current request for valve controller that is controlled with negative control signal.

o_ParameterError

BOOL

FALSE/TRUE

True if there is an incorrect parameter value in any of the FB’s inputs.

 

CODESYS 3.5CODESYS 3.5

Output variable name

Data type

Range

Description

o_PosDirCurrentRequest

UINT

0..2500 mA

Current request for valve controller that is controlled with positive control signal.

o_NegDirCurrentRequest

UINT

0..2500 mA

Current request for valve controller that is controlled with negative control signal.

o_ParameterError

BOOL

FALSE/TRUE

True if there is an incorrect parameter value in any of the FB’s inputs.

o_IllegalControlRequestInStartup

BOOL

FALSE/TRUE

True if unexpected control request occurs. i_Control is not 0 when i_Enable is set to true.

Example code

See also

 

Source file Topic000332.htm

Last updated 13-Jun-2024