Dual Loop Auxiliary Encoder, Using the CE Command

Dual Loop (Auxiliary Encoder)

The DMC-3415 provides an interface for a second encoder except when configured for stepper motor operation or circular compare. Please note, the DMC-3425 has only a single encoder per axis. When used, the second encoder is typically mounted on the motor or the load, but may be mounted in any position. The most common use for the second encoder is backlash compensation, described below.

The second encoder may be a standard quadrature type, or it may provide pulse and direction. The controller also offers the provision for inverting the direction of the encoder rotation. The main and the auxiliary encoders are configured with the CE command. The command form is CEa, where the parameter a equals the sum of two integers m and n. m configures the main encoder and n configures the auxiliary encoder.

NOTE: This operation is not available when the DMC-3415 is configured for a stepper motor.

Using the CE Command

m= Main Encoder

Second Encoder

0	Normal quadrature		0	Normal quadrature

1	Pulse & direction	4		Pulse & direction

2	Reverse quadrature	8		Reversed quadrature

3	Reverse pulse & direction	12		Reversed pulse & direction

For example, to configure the main encoder for reversed quadrature, m=2, and a second encoder of pulse and direction, n=4, the total is 6, and the command for the A axis is

CE 6

Additional Commands for the Auxiliary Encoder

The command, DEa can be used to define the position of the auxiliary encoder. For example, DE 500

sets the initial value.

The position of the auxiliary encoder may be interrogated with the command, DE?. The auxiliary encoder position may be assigned to variables with the instructions

V1= _DEA

The command, TD a,b,c,d, returns the current position of the auxiliary encoder.

The command, DV a,b,c,d, configures the auxiliary encoder to be used for backlash compensation.

Backlash Compensation

There are two methods for backlash compensation using the auxiliary encoder:

1.Continuous dual loop

2.Sampled dual loop

To illustrate the problem, consider a situation in which the coupling between the motor and the load has a backlash. To compensate for the backlash, position encoders are mounted on both the motor and the load.

98 • Chapter 6 Programming Motion

DMC-3425

DMC-3425 specifications

The Galil DMC-3425 is a sophisticated motion controller known for its versatility and high performance in various industrial applications. Designed primarily for multi-axis control, it is well-suited for robotics, CNC machinery, and automated manufacturing systems.

One of the standout features of the DMC-3425 is its ability to control up to 32 axes simultaneously, providing unparalleled flexibility for complex motion tasks. This capability is enhanced by its advanced motion algorithms that ensure smooth and precise movements, essential for high-quality manufacturing and assembly processes. The controller supports a variety of motor types, including servo, stepper, and brushless motors, making it compatible with a wide range of existing equipment.

In terms of connectivity, the DMC-3425 offers an extensive selection of communication options. It supports Ethernet, RS-232, and RS-485 interfaces, allowing for seamless integration with various industrial networks, including EtherCAT and CANopen. This connectivity is vital for real-time data exchange and remote monitoring, enhancing overall system efficiency.

The controller is powered by Galil's innovative software architecture, which includes the DMC programming language. This user-friendly language enables engineers to create complex motion profiles easily, with support for trajectory generation, coordinate transformations, and PID control. The DMC-3425 also features built-in commands for motion profiling, including linear and circular interpolation, allowing for sophisticated path planning.

Moreover, the DMC-3425 comes equipped with an integrated programming environment that facilitates rapid application development. Users can simulate motion profiles before implementation, reducing downtime and minimizing errors. This environment is designed for quick learning, making it accessible even for those new to motion control.

Additionally, the Galil DMC-3425 features a robust safety architecture. It includes over-temperature detection, emergency stop inputs, and configurable limits for position and speed, ensuring safe operation in various environments.

Overall, the Galil DMC-3425 is a powerful and flexible motion controller that combines advanced technologies with user-friendly design. Its ability to handle multiple axes, extensive connectivity options, and comprehensive programming environment make it a top choice for manufacturers seeking to enhance automation and improve productivity in their operations.

Galil DMC-3425 Dual Loop Auxiliary Encoder, Using the CE Command, Backlash Compensation

Models: DMC-3425