Overview

Control channel access functions This group defines all functions for access to control parameters like setpoint or actual value.

Collaboration diagram for Control Channel Access:

Functions
long	LCC_EnableControlLoop (dev_hdl ChanHdl, int Enable)
	Enables / disables a control loop. More...

long	LCC_GetSetPoint (dev_hdl ChanHdl, double *pfSetPointValue)
	Query setpoint value from device object. More...

long	LCC_GetSwScalingParam (dev_hdl ChanHdl, double pfScalingFactor, double pfScalingOffset)
	Read software scaling parameters. More...

long	LCC_IsControlLoopEnabled (dev_hdl ChanHdl)
	Query if a control loop is enabled. More...

long	LCC_ReadActualValue (dev_hdl ChanHdl, double *pfActualValue)
	Read actual value from device. More...

long	LCC_ReadActualValueUnscaled (dev_hdl ChanHdl, double *pfActualValueRaw)
	Read actual value from device - bypass scaling. More...

long	LCC_ReadStatus (dev_hdl ChanHdl, unsigned long *pdwStatus)
	Read additional status information from device. More...

long	LCC_SetPIDParameter (dev_hdl ChanHdl, int PIDParamId, double Value)
	Set the PID parameters of a certain control channel. More...

long	LCC_SetSwScalingOn (dev_hdl ChanHdl, int ScalingOn)
	Enable / disable software scaling. More...

long	LCC_SetSwScalingParam (dev_hdl ChanHdl, double fScalingFactor, double fScalingOffset)
	Set software scaling parameters. More...

long	LCC_WriteSetPoint (dev_hdl ChanHdl, double fSetPointValue)
	Write setpoint value to controller device. More...

long	LCC_WriteSetPointUnscaled (dev_hdl ChanHdl, double SetPointValueRaw)
	Write setpoint value to controller device - bypass scaling stage. More...

Function Documentation

long LCC_EnableControlLoop	(	dev_hdl	ChanHdl,
		int	Enable
	)

Enables / disables a control loop.

If the control loop is enabled, then the output value is calculated periodically.

Parameters

ChanHdl	Valid handle of a controller channel
Enable	1 = enable, 0 = disable

Returns: Error code - ERR_NOERR indicates success

See also: LCC_IsControlLoopEnabled()

Examples:: capi_dynamic_controller_test.cpp, capi_pressure_control_test.cpp, and capi_qmixqplus_test.cpp.

long LCC_GetSetPoint	(	dev_hdl	ChanHdl,
		double *	pfSetPointValue
	)

Query setpoint value from device object.

This function does not return the real setpoint value of the device but only the cached setpoint value entered by writeSetPoint()

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[in]	pfSetPointValue	The setpoint value read from device

Returns: Error code - ERR_NOERR indicates success

long LCC_GetSwScalingParam	(	dev_hdl	ChanHdl,
		double *	pfScalingFactor,
		double *	pfScalingOffset
	)

Read software scaling parameters.

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[out]	pfScalingFactor	The scaling factor multiplied with field value
[out]	pfScalingOffset	The scaling offset added to field value

See also: LCC_SetSwScalingParam()

Return values

ERR_NOERR	indicates success
-ERR_NOTSUP	Linear scaling not supported (i.e. if channel uses a different kind of scaling like PT100 scaling)

long LCC_IsControlLoopEnabled ( dev_hdl ChanHdl )

Query if a control loop is enabled.

If the control loop is enabled, then the output value is calculated periodically.

Parameters

ChanHdl Valid handle of a controller channel

Return values

1	- Control channel is enabled
0	- Control channel is disabled
<0	- Error code

See also: LCC_EnableControlLoop()

Examples:: capi_qmixqplus_test.cpp.

long LCC_ReadActualValue	(	dev_hdl	ChanHdl,
		double *	pfActualValue
	)

Read actual value from device.

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[out]	pfActualValue	Returns the actual controller value

Returns: Error code - ERR_NOERR indicates success

Examples:: capi_dynamic_controller_test.cpp, capi_pressure_control_test.cpp, and capi_qmixqplus_test.cpp.

long LCC_ReadActualValueUnscaled	(	dev_hdl	ChanHdl,
		double *	pfActualValueRaw
	)

Read actual value from device - bypass scaling.

Reads the actual value from the device bypassing the scaling stage of the channel. Reads the unprocessed value directly.

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[out]	pfActualValueRaw	Unprocessed actual value (no scaling)

Returns: Error code - ERR_NOERR indicates success

long LCC_ReadStatus	(	dev_hdl	ChanHdl,
		unsigned long *	pdwStatus
	)

Read additional status information from device.

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[out]	pdwStatus	Stores the status read from device

Returns: Error code - ERR_NOERR indicates success

long LCC_SetPIDParameter	(	dev_hdl	ChanHdl,
		int	PIDParamId,
		double	Value
	)

Set the PID parameters of a certain control channel.

See also: PIDParameterId for a list of all available parameters. If you create a dynamic control channel, the you need to set all PID parameters before you enable the channel via LCC_EnableControlLoop().

Parameters

ChanHdl	Valid handle of a controller channel
PIDParamId	PID parameter identifier -

See also: PIDParameterId for a list of all PID parameters

Parameters

Value The value for the PID parameter given in PIDParamId

Returns: Error code - ERR_NOERR indicates success

Examples:: capi_dynamic_controller_test.cpp, and capi_pressure_control_test.cpp.

long LCC_SetSwScalingOn	(	dev_hdl	ChanHdl,
		int	ScalingOn
	)

Enable / disable software scaling.

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[in]	ScalingOn	1 = Scaling on, 0 = Scaling off

Returns: Error code - ERR_NOERR indicates success

long LCC_SetSwScalingParam	(	dev_hdl	ChanHdl,
		double	fScalingFactor,
		double	fScalingOffset
	)

Set software scaling parameters.

These parameters are used to scale the measured value from device. These scaling parameters are independent from the device scaling parameters and the scaling is performed on the local machine. Scaled Value = (Process Value * Scaling Factor) + Scaling Offset. The default value for Scaling Factor is 1 and for Scaling Offset is 0.

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[in]	fScalingFactor	The scaling factor to multiply with field value
[in]	fScalingOffset	The scaling offset ro add to field value

Return values

ERR_NOERR	indicates success
-ERR_NOTSUP	Linear scaling not supported (i.e. if channel uses a different kind of scaling like PT100 scaling)

See also: LCC_GetSwScalingParam()

long LCC_WriteSetPoint	(	dev_hdl	ChanHdl,
		double	fSetPointValue
	)

Write setpoint value to controller device.

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[in]	fSetPointValue	The setpoint value to write

Returns: Error code - ERR_NOERR indicates success

Examples:: capi_dynamic_controller_test.cpp, capi_pressure_control_test.cpp, and capi_qmixqplus_test.cpp.

long LCC_WriteSetPointUnscaled	(	dev_hdl	ChanHdl,
		double	SetPointValueRaw
	)

Write setpoint value to controller device - bypass scaling stage.

Parameters

[in]	ChanHdl	Valid handle of open controller channel
[in]	SetPointValueRaw	Unprocessed set point value (no scaling)

Returns: Error code - ERR_NOERR indicates success

Overview

Functions

Function Documentation