Fagor 8025 T CNC, Operating Manual

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3. DIVIDING FACTOR FOR FEEDBACK SIGNALS
Parameters P620(5), P620(6), P613(8) and P613(7) are used together with P602(6), P602(5), P612(5) and P614(5) which
indicate the multiplying factor to be applied to the feedback signals of the X, Z, 3rd and 4th axes respectively.
X axis Z axis 3rd axis 4th axis
P602(6) P602(5) P612(5) P614(5)
P620(5) P620(6) P613(8) P613(7)
Indicate whether the feedback signals are divided (=1) or not (=0).
P620(5)=0, P620(6)=0, P613(8)=0 y P613(7)=0 They are not divided
P620(5)=1, P620(6)=1, P613(8)=1 y P613(7)=1 They are divided by two.
Example: We wish to obtain a resolution of 0.01 mm with a squarewave encoders mounted on the X axis with 5mm
pitch ballscrew.
Nr of pulses = ballscrew pitch / (Multiplying factor x Resolution)
With P602(6)=0 & P620(5)=0 x4 multiplying factor Nr of pulses = 125
With P602(6)=1 & P620(5)=0 x2 multiplying factor Nr of pulses = 250
With P602(6)=0 & P620(5)=1 x2 multiplying factor Nr of pulses = 250
With P602(6)=1 & P620(5)=1 x1 multiplying factor Nr of pulses = 500
Version 7.6 (July 2001)
1. G75 AFFECTED BY FEEDRATE OVERRIDE
From this version on, there is a new machine parameter indicating whether G75 is affected by the feedrate override or
not.
P623(1) = 0Not affected. It is always at 100%, like in previous versions.
P623(1) = 1It is affected by the Feedrate override.
2. FEEDBACK FACTOR.
From this version on, there is a new machine parameter to set the resolution of an axis having an encoder and a leadscrew.
P819 Feedback factor for the X axis P820 Feedback factor for the 3rd axis
P821 Feedback factor for the Z axis P822 Feedback factor for the 4th axis
Values between 0 and 65534. The “0” value indicates that this feature is not being used.
Use the following formula to calculate the “Feedback Factor” :
Feedback factor = (Gear Ratio x Leadscrew pitch / Number of Encoder pulses) x 8.192
Examples: Gear Ratio 1 1 2 1
Leadscrew pitch 5000 6000 6000 8000 (microns)
Encoder 2500 2500 2500 2500 (pulses/turn)
Feedback factor 16384 19660.8 39321.6 26214.4
The machine parameters only admit integer values and sometimes the “Feedback Factor” has decimals. In those cases,
assign the integer part to the machine parameter and use the leadscrew compensation table to make up for the decimal
part.
The values to be entered in the table are calculated with the following formula:
Leadscrew position = Leadscrew Error (microns) x Integer of feedback factor / decimals of the feedback factor
For example: Gear ratio = 1 Leadscrew pitch = 6000 Encoder = 2500
Feedback factor = 19660.8 Machine parameter = 19660
For a leadscrew error of 20 microns Leadscrew position = 20 x 19660 / 0.8 = 491520
Going on with the calculation, we come up with the following table.
Leadscrew position Leadscrew error
P0 = -1966.000 P1 = -0.080
P2 = -1474.500 P3 = -0.060
P4 = -983.000 P5 = -0.040
P6 = -491.500 P7 = -0.020
P8 = 0 P9 = 0
P10 = 491.500 P11 = 0.020
P12 = 983.000 P13 = 0.040
P14 = 1472.500 P15 = 0.060
P16 = 1966.000 P17 = 0.080
3. NEW MODEL
From this version on, the new model TLI is now available.
It offers the same features as the TGI model and it is sold together with the motors and ACS drives..