RoboteQ AX2550, AX1500 user manual RS232 Communication with the Encoder Module, Important Notice

Installing, Connecting and Using the Encoder Mod-

The actual formula is as follows:

Distance = (Destination - Counter value) / Divider

Where: divider is a configurable parameter of value 1, 2, 4, 8, 16, 32, 64 or 127

If computed distance is less than -127, then reported distance is -127

If computed distance is larger than +127, then reported distance is +127

Destination= 50,050

Counter= 50,000

distance	at divider
50	1
25	2
12	4
6	8
3	16
1	32
0	64
0	128

FIGURE 46. Small distance computation example

Destination= 50,000

Counter= 45,000

distance	at divider
127	1
127	2
127	4
127	8
127	16
127	32
78	64
39	128

FIGURE 47. Large distance computation example

Important Notice

Encoders do not report an absolute position value but a count that is relative to the point where the motor shaft was at power up. It is typically necessary to have the motors moved to a “home” position and reset the counters at that reference point.

RS232 Communication with the Encoder Module

The contains its own Microcontroller and firmware in Flash. When present, it responds to a large set of dedicated commands and queries via the controller’s serial port. See “RS232 Encoder Command Set” on page 145.

78 AX1500 Motor Controller User’s Manual Version 1.9b. June 1, 2007