Specifications

Examples and tips
PROGRAMMING MANUAL 232
Revision 5.0
Example 1
fig. 19
The mechanical system consists of a simple rotary table. A servo motor with
13-bit incremental encoder is used. The gear ratio of the gearbox is 1:10.
The desired user units are degree of angle. This system can be described
with the following equations:
The combination of these equations results in:
And therefore:
From this equation, we can derive the values for Pn202, Pn203 and UNITS,
given the following restrictions and recommendations:
1. Pn202 and Pn203 are integers.
2. UNITS must not have an infinite number of decimal digits. This can
create rounding errors that result in small position errors that add up to
large accumulative position errors.
3. For reasons of stability, it is necessary to avoid situations where Pn202/
Pn203 is less than 0.01 or greater than 100. It is recommended that
Pn202/Pn203 is approximately 1.
1:10 Gear
13-bit
incremental
encoder
Full turn = 360
M
1 motor_revolution = 2
13
encoder_count
s
10 motor_revolution = 1 machine_cycle
1 machine_cycle = 360
o
.
.
.
.
.
Pn202
Pn203
UNITS = =
.
2
13
13
encoder_counts
1 motor_revolution
1 machine_revolution
10 motor_revolution
360
1 machine_revolution
o
360
2 10
degree
encoder_counts
.
.
.
..
.
Pn202
Pn203
UNITS =
.
2
13
10
360
.