labbCAN Controller API

Overview

Controller specific functions.

This module defines all labbCAN controller specific functions, identifiers and data types for control of measurement and control devices attached to the labbCAN bus. Controller modules are used for closed loop control like heating, cooling or something else. The control is performed by an internal control algorithm like PID or Fuzzy control. The labbCAN controller module offers a device independent API for access to all supported labbCAN measurement and control devices.

See also

See Controller Library for a detailed introduction and general overview of controller library.

Collaboration diagram for labbCAN Controller API:

Modules
	Channel Initialisation
	Controller module channel initialisation functions This group defines all functions to initialise controller channels properly.
	Common Channel Functions
	Common channel specific auxiliary functions.
	Control Channel Access
	Control channel access functions This group defines all functions for access to control parameters like setpoint or actual value.

Enumerations
enum	LoopOutType { ANALOG, DIGITAL, DIGITAL_PWM, PUMP_FLOW }
	Control loop output type This enumeration defines the output types for dynamic control channels. More...
enum	PIDParameterId {   PID_PARAM_K = 0, PID_PARAM_T_I, PID_PARAM_T_D, PID_PARAM_DERIVATIVE_GAIN_LIMIT,   PID_PARAM_T_T, PID_PARAM_MAX_U, PID_PARAM_MIN_U, PID_PARAM_DISABLED_U,   PID_PARAM_INITIAL_SETPOINT, PID_PARAM_SAMPLE_TIME, PID_PARAM_COUNT }
	ID parameter identifier Identifier for all PID control loop parameter that can be changed via LCC_SetPIDParameter. More...

Enumeration Type Documentation

enum LoopOutType

Control loop output type This enumeration defines the output types for dynamic control channels.

See also

LCC_CreatePIDControlChannel

Enumerator
ANALOG	plain analog output channel that can output an analog value
DIGITAL	digital output that can output 0 or 1 - e.g. to switch a heating on / off
DIGITAL_PWM	uses a digital output to generate a PWM by switching the channel on / off
PUMP_FLOW	uses a pump a control loop output - e.g. for pressure controlled dosage

enum PIDParameterId

ID parameter identifier Identifier for all PID control loop parameter that can be changed via LCC_SetPIDParameter.

Before your can use a control loop, you should properly set all control loop parameters. You can use the QmixElements software for PID parameter testing and PID tuning.

See also

LCC_CreatePIDControlChannel

Enumerator
PID_PARAM_K	proportional gain K
PID_PARAM_T_I	integral time constant Ti
PID_PARAM_T_D	differential time constant Td.
PID_PARAM_DERIVATIVE_GAIN_LIMIT	the value the derivative gain is limited to. The derivative gain is computed from control loop error K and Td.
PID_PARAM_T_T	value for dead time correction
PID_PARAM_MAX_U	maximum control value
PID_PARAM_MIN_U	minimum control value
PID_PARAM_DISABLED_U	fixed control value that is set when the control loop is disabled.
PID_PARAM_INITIAL_SETPOINT	the initial setpoint if no setpoint has been set (default 0)
PID_PARAM_SAMPLE_TIME	sample time of pid control loop in milliseconds
PID_PARAM_COUNT	this is just a delimter and not a real param