Omron trajexia CJ1W-MCH72, Operation Manual

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How-to’s Section 5-1
289
called limited axis or finite axis. A typical example of a limited axis is a ball
screw, as shown in . When the mechanical system always moves in the same
direction, it reaches the overflow of the multiturn counter. In this case, the
value of Pn205 must guarantee that the overflow always occurs in the same
position with respect to the machine. This is called unlimited axis and a typical
example of it is a turntable shown in . It can be achieved with the following
equation: the smallest value of
m such that:
Because n and m are integers: Pn205 = m – 1. This setting is explained in the
following example.
5-1-3-4 Example 2
The mechanical system consists of simple rotary table shown in the figure. A
servo motor with 16-bit absolute encoder is used. The gear ratio of the
gearbox is 1:10. The desired user units are degree of angle. The rotary table is
divided in six sections of 60 degrees each. Therefore the machine_cycle is 60
degrees.
When we apply the last equation to the above, we get:
Simplification of this equation gives:
This results in:
We calculate the parameters as we did in example 1. This gives:
n machine_cycles = m motor_revolution
. .
1:10 Gear
16-bit
absolute
encoder
Full turn = 360
M
60
10 motor_revolution = 1 machine_revolution = 6 machine_cycle
. . .
5 motor_revolution = 3 machine_cycle
. .
Pn205 = 5-1 = 4
UNITS = 2 = 2048
11
Pn202 = 32
Pn203 = 36