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Estop

Overview

Overview

Description

The EStop block is used to trigger an emergency error stop event on a given motion supervisor. This stops motion on all mapped axes within the pre-configured e-stopping time. During the course of an EStop, the motion state changes from Stopping Error to Error. No fault flags are raised and the related amps remain enabled. However, since this action results in an error state, a motion reset is required in order to perform further motions on the related axes.

Example

This example shows how a control algorithm might be built in a vertical application where the force in the up direction has a higher limit than the down direction. This is because to move up, you must fight gravity, and to move down, gravity is helping. To control the torque limits an Asymetric clip is used to limit the torque, and a complimentary Deadband filter is setup attached to an EStop command to stop motion if the command does exceed the limits of the Clip. Upon exceeding the limits, the faulting torque command is written to the User Buffer to help determine what the cause of the fault was.

The EStop is triggered when the Commanded Torque exceeds the limits of the DeadBand.


The configuration values for this block are as follows:

 
Motion Supervisor Number The number of the motion supervisor on which to perform the EStop action. This number may be absolute or linked to the Model Number.

Evaluate Block

This block allows you to specify whether the block executes Every Sample, Every Other Sample (Odd or Even), or Every Fourth Sample (and specify the First, Second, Third, or Fourth). This provides greater flexibility in controlling the execution of a model and to preserve performance for other areas of motion control.

User Defined Block Priority When selected, allows you to enter a Priority Code to modify Execution Ordering of this block. For more information, see Block Execution Order and User Defined Block Priority.
Priority For an explanation of how the Priority field is used by the MechaWare Model Downloader, see Block Execution Order and User Defined Block Priority.
User Data 0 Application-specific data. See User Data Storage.
User Data 1 Application-specific data. See User Data Storage.

Matlab/Simulink

Simulink Interface

The Itrp (opt) output is an output which only relates to simulation.

Note: This output is only used when simulating within Simulink and is ignored when the model is downloaded to a controller.

The Interrupt pin is used on all Motion Simulation blocks to allow them to communicate with a central trajectory planner, interpret events, and change the trajectory as required. When Bit 3 is triggered by the EStop block, the trajectory information is used to simulate a EStop Motion to a Zero Velocity using the EStop Time parameter specified in the Trajectory Planner.

The Motion Supervisor Number of the EStop block specifies which motion supervisor to issue the EStop action to (axis or motor number when using default mappings).

The block has two user data fields (User Data 0, User Data 1) to store application-specific data for convenient storage and retrieval. For more information, see User Data Storage.

The block's update schedule is determined by the Evaluate Block. The following Parameter Dialog Box can be opened by double-clicking on the block in a Simulink model:

 

C++ API

EstopBlock

Declaration

Public Method

 
class ESTOPBlock: public virtual Block
{
public:
	// User accessible coefficients
	long MSNumber;
};
 

Required Header: mechaware.h

Description

The Estop block provides a controlled way to bring motors to a stop in a way that further motion cannot continue until the state has been restored (Motion_Reset). Similar to the STOP block, the rate of deceleration is implied by the motion supervisor’s pre-configured e-stopping time (MotionConfig.decelTime.eStop). However, in contrast to the regular stop time, the eStop time is conventionally an order of smaller magnitude resulting in more rapid deceleration. The e-stop action is issued on the rising-edge of the block’s Execute input value.

Parameters

long

MSNumber Motion Supervisor number

Methods

Block Methods

See Also

Stop | Abort | MOTION_RESET | AMP_ENABLE

 

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