Galil DMC-13X8 Dual Loop Auxiliary Encoder, Using the CE Command, = Main Encoder Second Encoder

MCX

WT100;'STABILIZE

JP#LOOP; 'KEEP CORRECTING UNTIL ERROR IS WITHIN 'TOLERANCE

#END; 'END #CORRECT SUBROUTINE, RETURNING TO CODE

SPX=spx

EN

Dual Loop (Auxiliary Encoder)

The DMC-13X8 provides an interface for a second encoder for each axis except for axes configured for stepper motor operation and axis used in circular compare. 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 CE x,y,z,w where the parameters x,y,z,w each equal the sum of two integers m and n. m configures the main encoder and n configures the auxiliary encoder.

Using the CE Command

m= Main Encoder

n=

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 X axis is

CE 6

Additional Commands for the Auxiliary Encoder

The command, DE x,y,z,w, can be used to define the position of the auxiliary encoders. For example, DE 0,500,-30,300

sets their initial values.

The positions of the auxiliary encoders may be interrogated with the command, DE?. For example DE ?,,?

returns the value of the X and Z auxiliary encoders.

The auxiliary encoder position may be assigned to variables with the instructions V1= _DEX

The command, TD XYZW, returns the current position of the auxiliary encoder.

The command, DV XYZW, configures the auxilliary encoder to be used for backlash compensation.

Chapter 6 Programming Motion • 98 USER MANUAL