SMC_Homing (FB)¶

FUNCTION_BLOCK SMC_Homing

This function block causes the execution of a homing sequence. If SMC_Homing is executed, the axis is moved at fVelocityFast in the direction specified by nDirection as long as the reference switch is open (bReferenceSwitch := TRUE).

Once the reference switch is closed (bReferenceSwitch := FALSE), the axis is decelerated and driven at fVelocitySlow (the direction depends on the homing mode). At the point at which the reference switch opens again (bReferenceSwitch := TRUE), the following actions are performed: the index pulse and index position are used (optionally), the reference position fHomePosition is set, the drive is stopped. (The order of these actions depends on the homing mode, see SMC_HOMING_MODE.)

InOut:

Scope	Name	Type	Initial	Comment
Inout	`Axis`	AXIS_REF_SM3
Input	`bExecute`	`BOOL`		Rising edge: Starts the execution of the function block.
	`fHomePosition`	`LREAL`		Home position; set after homing (in technical unit [u])
	`fVelocitySlow`	`LREAL`		Low velocity; used to drive out of the reference switch [u/s]
	`fVelocityFast`	`LREAL`		High velocity; used until reference switch is found [u/s]
	`fAcceleration`	`LREAL`		Value of the acceleration (increasing energy of the motor) [u/s^2]
	`fDeceleration`	`LREAL`		Value of the deceleration (decreasing energy of the motor) [u/s^2]
	`fJerk`	`LREAL`		Value of the Jerk [u/s^3]
	`nDirection`	MC_Direction	negative	The direction for the fast movement searching the reference switch. (`positive` or `negative`)
	`bReferenceSwitch`	`BOOL`	TRUE	`TRUE`: The switch is open (the drive is not in the switch) `FALSE`: The switch is closed (the drive is in the switch)
	`fSignalDelay`	`LREAL`		Time [s] for `bReferenceSwitch` to be transmitted.
	`nHomingMode`	SMC_HOMING_MODE	FAST_BSLOW_S_STOP	Homing mode
	`bReturnToZero`	`BOOL`		`TRUE`: Moves to position zero after homing.
	`bIndexOccured`	`BOOL`		`TRUE`: Index pulse has been detected, the index position is stored in input `fIndexPosition`.
	`fIndexPosition`	`LREAL`		Position where index occured
	`bIgnoreHWLimit`	`BOOL`		Disables the limit switch handling in the driver by setting `bHWLimitEnable` to `FALSE` during homing. Please note that for most servo drives, this is necessary but not sufficient to disable the limit switch handling in the drive. Often, the limit switch handling in the drive must be deactivated by other means before calling SMC_Homing, and reactivated when SMC_Homing is done. (For example by writing a drive-specific configuration object.)
Output	`bDone`	`BOOL`		`TRUE`: Homing has been done.
	`bBusy`	`BOOL`		`TRUE`: FB is not idle.
	`bCommandAborted`	`BOOL`		`TRUE`: Commanded motion has been interrupted by any motion FB acting on the same axis except `MoveSuperImposed`.
	`bError`	`BOOL`		`TRUE`: Error has occured within function block.
	`nErrorID`	`SMC_ERROR`		Error identification*
	`bStartLatchingIndex`	`BOOL`		For some homing modes, the index pulse is evaluated. `TRUE`: Storing of the index pulse has been started and must be done by the application. The result is expected in the inputs `bIndexOccured` and `fIndexPosition`.