Command: Stop (Closed Loop) (6)

Supported Axes:	Position and Velocity Axes
Supported Control Modes:	All

See the Commands Overview topic for basic command information and how to issue commands from PLCs, HMIs, etc.

Command Parameters

#	Parameter Description	Range
1	Deceleration Rate (pos-units/s2)	>0

Description

This command stops the axis in closed loop control, bringing the velocity to zero at the specified Deceleration Rate. The behavior of this command depends on the type of control of the axis at the moment this command is received:

Position PID
The Target Position stops by ramping the current Target Velocity to zero using the specified Deceleration Rate, while remaining in position control.
Position I-PD
If the last motion command was Move Absolute (I-PD) (28) or Move Relative (I-PD) (29),the Target Position will be moved toward the current position to ensure a quicker yet smooth stop. Otherwise, the Target Position will be stopped by rampingthe current Target Velocity to zero using the specified Deceleration Rate, while remaining in position control.
Velocity PID
The Target Velocity will ramp down from the current velocity to zero using the specified Deceleration Rate, while remaining in velocity control.
Velocity I-PD
If the last motion command was Move Velocity (I-PD) (38), the Target Velocity will stop immediately. Otherwise, the velocity will ramp down from the current velocity to zero using the specified Deceleration Rate, while remaining in velocity control.
Open Loop
The axis transitions to closed-loop control and ramps the velocity to zero using the specified Deceleration Rate in V/sec.

If you wish to stop the axis, but not remain in closed loop control, consider using the Stop (Open Loop) (22).

Closed Loop Stopping of the Actual versus Target Position

The Stop (Closed Loop) command will stop the Target Position. Therefore, if the Actual is lagging significantly behind the target, the axis will actually continue moving until it reaches the stopped Target Position. If the Actual is lagging and you want the Actual Position to stop immediately, you can put the axis in open loop control (which sets the Target Position to the Actual Position) for one loop time, then issue the Stop (Closed Loop) command. This can be done in a user program. In the first step, issue the Open Loop Rate command. In the Output command parameter, put the Control Output. This will keep the Control Output from changing drastically. Then choose the Immediate link type and make the next step issue a Stop (Closed Loop) command. On most well-tuned systems, this issue is typically not a concern.

Status Bits

In Position Bit

The In Position status bit will not be set. Do not attempt to use the In Position bit to tell if the axis has stopped after a Stop (Closed Loop) (6) command.

Target Generator State Bits

The Target Generator bits in the Status Bits register indicate which portion of the move the axis is currently in. These bits are useful when programming complex motion sequences.

Target Generator Done bit

This bit indicates the move is complete, which occurs when the Target Position has stopped.

Target Generator State A and B bits

B	A	Description
0	0	Done
0	1	Reserved
1	0	Reserved
1	1	Decelerating to zero velocity