Y_DirectControl

This block allows direct access to any of five possible control modes available for the specified axis. For example, Y_DirectControl makes it possible to perform open loop velocity control for winding applications. In any control mode, the IEC application program can apply an algorithm to directly command position, velocity, or torque at every application task scan.

Parameters

*	Parameter	Data Type	Description
VAR_IN_OUT
B	Axis	AXIS_REF	Logical axis reference. This value can be located on the Configuration tab in the Hardware Configuration (logical axis number).
VAR_INPUT				Default
B	Enable	BOOL	The function will continue to execute every scan while Enable is held high and there are no errors.	FALSE
V	ControlMode	Yt_ControlMode	ControlMode: 1=Position, 2=Velocity, 3=Torque, 4=Position with Torque Feed Forward, 5=Velocity with Torque Feed Forward	INT#0
E	Position	LREAL	A positive or negative value within the coordinate system in user units.	LREAL#0.0
E	Velocity	LREAL	Velocity in user units/second. See notes below.	LREAL#0.0
E	Acceleration	LREAL	Value of the acceleration in user units/second^2 (acceleration is applicable with same sign of torque and velocity). Used in control modes 4 and 5.	--
E	Torque	LREAL	Value of the torque (in percentage of rated torque).	LREAL#0.0
V	FilterTimeConstant	LREAL	Moving average filter specified in seconds. See below for details.	LREAL#0.0 (No Filter)
E	BufferMode	MC_BufferMode	The behavior of the axis could be Aborting or Buffered MC_BufferMode#Aborting MC_BufferMode#Buffered	MC_BufferMode#Aborting
VAR_OUTPUT
E	Busy	BOOL	Set high upon the rising edge of the Execute input, and reset when Done, CommandAborted, or Error is true. In the case of a function block with an Enable input, a Busy output indicates the function is operating, but not ready to provide Valid information. (No Error)
E	Active	BOOL	For buffered modes, this output is set high at the moment the block takes control of the axis. For non buffered modes, the outputs Busy and Active have the same value.
E	CommandAborted	BOOL	Set high if motion is aborted by another motion command or MC_Stop. This output is cleared with the same behavior as the Done output.
B	Error	BOOL	Set high if an error has occurred during the execution of the function block. This output is cleared when 'Execute' or 'Enable' goes low.
E	ErrorID	UINT	If Error is true, this output provides the Error ID. This output is reset when 'Execute' or 'Enable' goes low.

Notes

Use the appropriate input(s) for the selected ControlMode as follows:
In Position mode (1), Velocity input is the velocity feedforward. The Torque input is ignored.
In Velocity Mode (2), the Torque input is a torque limit.
In Torque Mode (3), the Velocity input is a velocity limit.
In Position Mode with Torque feedforward (4), the Torque input is the torque feedforward, Velocity input is the velocity feedforward.
In Velocity Mode with Torque feedforward (5), the Torque input is the torque feedforward.
The acceleration input is never used. The user must calculate the required command profile.
The FilterTimeConstant is specified in seconds. This feature is applicable when the IEC application task rate in which this function is executing is slower than the Motion Engine update. If this time constant is set to the IEC task interval (e.g. 0.01 for a 10 ms scan), then the filter calculates additional command data (an interpolated value) at each Motion Engine update, reaching the set point just before the next IEC application scan. If set to zero or not connected, the command position is changed to the user specified value only at the end of each IEC application task, causing small stair stepping response. Rising edge of Enable is required for a new FilterTimeConstant to be applied.
If it is necessary to transition from Torque to Position mode, the Y_HoldPosition function block is useful in making that transition.
Buffered mode is only supported when transitioning between positioning function blocks. Care must be taken to prevent abrupt or unintended motion.

Error Description

See the Function Block ErrorID List

Example 1
Y_DirectControl configured in position mode.

Example 2

Y_DirectControl in position mode with filter time constant

Example 3

Y_DirectControl configured for velocity mode.