Electronic Gear - YASKAWA SGD7C-***AMAA*** Product Manual

12.8 Counter Function Module

12.8.2 Electronic Gear

Axis Type
There are two types of axes: finite-length axes that reset the current count to a specified value,
and infinite-length axes that do not reset the current count.
An infinite-length axis is used to reset the current count every rotation, such as when using a
conveyor belt. A finite length axis is used when it is not necessary to reset the current count
even when a rotation is completed, such as when operating within a set segment in a round-
trip operation or when rotating in one direction only.
Select the type of axes to use with fixed parameter No. 07 (Axis Selection).
If an infinite-length axis is selected, the current count after the change and the PI latching data
after the change will be given in a range from 0 to 1 less than the reset position of the infinite-
length axis.
Set the reset position of the infinite-length axis with parameter No. 13 (Maximum Value of
Rotary Counter (Infinite Length Axis Reset Position) (POSMAX)).
12.8.2 Electronic Gear
The electronic gear can be used when fixed parameter No. 08 (Reference Unit Selection) is set
to a value other than pulses (such as mm, deg, or inch).
Overview of the Electronic Gear
The electronic gear allows you to set the workpiece travel distance per pulse input to the
Counter Function Module.
For example, to move a workpiece 10 mm with the following type of device, the operation
depends on whether the electronic gear is used, as described below. If the electronic gear is
used, all that is required is to input the number of reference units based on the travel distance
without worrying about calculations based on the number of pulses.
12-58
Encoder pul e : 8,192
When the Electronic Gear Is Not Used
The device will move 6 mm for each rotation,
so the number of rotations required to move
the device 10 mm is 10 mm ÷ 6 mm/rotation
= 1.666 rotations.
The number of pulses per rotation is 2,048 ×
4 (multiplier) = 8,092 pulses, so the number
of pulses required for 1.666 rotations is
1.666 × 8,092, or 13,653 pulses. You must
perform this conversion on the host control-
ler and input 13,653 pulses as the reference.
PO MAX
0
Workpiece
Ball crew (pitch: 6 mm)
When the Electronic Gear Is Used
The machine conditions are defined in advance,
and the minimum reference unit, for example 1
μm, is set.
The number of reference units required to move
10 mm is 10 mm ÷ 1 μm, or 10,000. Therefore,
10,000 reference units must be input.