Overview

Description

The Demand is an output that is mapped to one of the Demand outputs of a motor. Each motor has 5 Demand outputs, and to operate a motor, one or more of these demand channels is required.

For a standard Torque Mode model, only Demand Channel 0 is used (or the Torque Output block can be used).

In a Velocity Mode model, Demand Channel 2 can be used to output raw torque for feed forwards, similar to velocity feed forward, acceleration feed forward and friction feed forward. However, the velocity is controlled by demand channel 3, where a velocity value should be commanded.

Position Mode requires demand channels 2-4. Where Position, Velocity, and feed forward torques are specified.

The block is updated at the update rate, determined by the Evaluate Block.

Motor Number	The number of the motor to which to send the output. This number may be absolute or linked to the Model Number.
Channel	The number of the demand channel on the motor to write.
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) or background. 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

Arc Tangent Simulink Block

The Motor Number of the Demand block specifies which Motor object is used for output.

The Channel defines which demand channel on the motor is written with the Demand value.

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

Arc Tangent Parameters Dialog Box

C++ API

DEMANDBlock

Declaration

Public Method

	class DEMANDBlock: public virtual Block { public: // User accessible coefficients };
	Required Header: mechaware.h

Description

The Demand block is used to connect the outputs of a model.

Methods

Block Methods