Yaskawa MP940 - Manual (Page 129)

MP940 Functions
4.4.7 PI Latch Function
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4.4.7 PI Latch Function
The PI latch function stores (i.e., latches) in a memory register the current position at the
moment an external signal is input (detected on the rising edge).
Select a special discrete input (PI input) as the external signal.
∗ 1. PI latch detection request = Operating mode (OW0002, bit 2)
∗ 2. PI detection position monitor = PI latch data (IL0006)
4.4.8 Electronic Gear
The electronic gear function enables the motor travel distance per input reference pulse to be
set to any value. It allows the host controller to perform control without having to consider
the machine gear ratio and the number of encoder pulses.
PINT
0
(+)
(-)
PINT
Counte
r’
s cou
nt register
Hardware check
PI latch detection request *1
1 µs min.
External signal
PI latch completed
signal
Position monitor at
PI detection *2
Workpiece Workpiece
Number of encoder
pulses: 2,048
Number of encoder
pulses: 2,048
Ball screw pitch:
6 mm Ball screw pitch: 6 mm
To move a workpiece 10 mm:
One revolution is equivelent to 6 mm, so
10 6 = 1.6666 (revolutions)
2048 x 4 (pulses) is equivalent to one revolution, so
1.6666 x 2,048x4 = 13,653 (pulses)
A total of 13653 pulses must be input as a refer-
ence.
The host controller needs to make this calculation.
÷
Reference unit: 1 µm
Machine conditions and reference unit
must be defined for the electronic gear
function beforehand.
To move a workpiece 10 mm:
Reference unit is 1 m, so
10 mm 1 m=10,000 pulses
µ
÷ µ
When Electric Gear Function is Not Used: When Electric Gear Function is Used: