AutofocusSetup Parameter

Default Value: 0

Minimum Value: None

Maximum Value: None

Units: None

Type: int

Parameter Settings and Values

This table shows the value of the configuration for the parameter setting.

Table: Parameter Settings, Configurations, and Values

Setting	Configurations	Value
Loop Polarity	Normal	0x00000000
Loop Polarity	Inverted	0x00000001
Autofocus Limits	Disabled	0x00000000
	Enabled (Absolute)	0x00000002
	Enabled (Relative)	0x00000004
Hold Input Polarity	Active Low	0x00000000
Hold Input Polarity	Active High	0x00000010
Motion Mode	Normal	0x00000000
Motion Mode	Additive	0x00000020
InPosition Mode	Use Autofocus Deadband	0x00000000
	Use Position Error	0x00000040
	Use Autofocus Error	0x00000080

HARDWARE: Autofocus does not apply when used with the GI4, the GL4, or the XL4s.

Use the AutofocusSetup parameter to configure settings related to autofocus behavior. The sections that follow give the possible settings for this parameter.

Loop Polarity

Normal is the default. The autofocus loop polarity is normal (positive error causes positive motion).

When you select Inverted, the autofocus loop polarity is reversed (negative error causes positive motion).

Autofocus Limits

Disabled is the default. There are no limits. The autofocus loop can command the axis to move to any position.

When you select Enabled (Absolute), the autofocus position limits are relative to the axis home position. Use the AutofocusLimitHigh Parameter and AutofocusLimitLow Parameter to specify the autofocus position limits.

For Example - Enabled (Absolute)

You select Enabled (Absolute), which sets the AutofocusSetup parameter to 0x2 on the X axis. Then you set the values of the AutofocusLimitLow parameter to -127 mm and the AutofocusLimitHigh parameter to 20 mm. The home position of the axis is at 0 mm. When the axis position is at -50 mm, you issue the AutofocusOn() function to enable autofocus.

Because the autofocus position limits are referenced to the home position and not the current position, the controller clamps the position command at -127 mm or 20 mm.

When you select Enabled (Relative), the autofocus position limits are relative to the position where autofocus was enabled. Autofocus is enabled when the AutofocusOn() is issued.

For Example - Enabled (Relative)

You select Enabled (Relative), which sets the AutofocusSetup Parameter to 0x4 on the X axis. Then you set the values of the AutofocusLimitLow parameter to -127 mm and the AutofocusLimitHigh parameter to 20 mm. The home position of the axis is at 0 mm. When the axis position is at -50 mm, you issue the AutofocusOn() function to enable autofocus.

Because the autofocus position limits are referenced to the current position and not the home position, the controller clamps the position command at -177 mm or -30 mm.

Hold Input Polarity

Active Low is the default. The autofocus loop is held when the digital input specified by the AutofocusHoldInput Parameter is low. For a differential input, this condition corresponds to a low input level. For an opto-isolated input, this corresponds to the optocoupler not being driven.

When you select Active High, the autofocus loop is held when the digital input specified by the AutofocusHoldInput parameter is high. For a differential input, this corresponds to a high input level. For an opto-isolated input, this condition corresponds to the optocoupler being driven.

Motion Mode

Normal is the default. The controller uses the output of the autofocus loop as the position command for the axis. In this mode, if you enable the autofocus feature, you cannot issue other motion commands until you disable autofocus.

When you select Additive, the controller adds the output of the autofocus loop to the position command for the axis. In this mode, you can issue other motion commands to the axis that will be added with the autofocus loop output. If you select Additive, you must specify Continuous focus mode for the $focusMode argument of the AutofocusOn() command.

Refer to the Autofocus Block Diagram on the Autofocus Functions page for more information.

InPosition Mode

Use Autofocus Deadband is the default. The drive uses the Autofocus Error to set the In Position bit of the Drive Status. When the Autofocus Error is less than the value that you specify for the AutofocusDeadband Parameter, the drive sets the In Position bit to TRUE.

You must turn on autofocus for the Use Autofocus Deadband setting to have an effect. If autofocus is off, the In Position bit behaves as if you selected the Use Position Error setting.

When you select Use Position Error, the drive uses the absolute value of the Position Error to set the In Position bit of the Drive Status. When the absolute value of the Position Error is less than the value that you specify for the InPositionDistance Parameter for a minimum of the quantity of time that you specify for the InPositionTime parameter, the drive sets the In Position bit to TRUE.

When you select Use Autofocus Error, the drive uses the Autofocus Error to set the In Position bit of the Drive Status. When the Autofocus Error is less than the value that you specify for the InPositionDistance Parameter for a minimum of the quantity of time that you specify for the InPositionTime Parameter, the drive sets the In Position bit to TRUE. You must specify the value of the InPositionDistance parameter in volts when you use this setting.

If you use the Use Autofocus Error setting while the autofocus mode is off or while you issue the AutofocusOff() function, the In Position bit stays set to TRUE.