Granite Devices GDtool 0.11 User manual

GDtool 0.11 manual
GDtool 0.11 manual
Document version 0.31
www.granitedevices.fi 1/19 2007-04-27

GDtool 0.11 manual
Table of Contents
Introduction............................................................................................................................. ...............3
equirements.................................................................................................................... .....................3
Cabling.................................................................................................................................. .................3
Installing software.......................................................................................................... ........................4
Introduction to servo system.............................................................................................. ....................4
Getting started with GDTool............................................................................................................ ........6
Description of basic functions............................................................................................... .............6
Configuring motor parameters................................................................................................................ 7
Position or velocity tuning.................................................................................................................... .11
Tuning the position mode..................................................................................................................... .13
Tuning the velocity mode................................................................................................................ ......15
Flasher.................................................................................................................................................. 18
Troubleshooting................................................................................................................ ....................19
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GDtool 0.11 manual
Introduction
GDTool software allows you to set VSD-A drive control loop parameters to match your control
system. You don't need additional hardware (oscilloscope for example) to get essential information
because GDTool reads data directly from drive and plot's it to your PC screen.
Requirements
●Windows1 operating system
●Parallel port
●VSD-A Drive connected to motor and power supply
●Cable or breakout board to connect your PC and Drive
Cabling
Please read VSD-A data sheet for hardware information. To connect drive and PC, use 25 pin D-
SUB cable or VSD-A breakout board. You can also build your own data cable according to following
schematics.
1 Windows Vista x64 is not supported
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Figure 1: Data cable schematic

GDtool 0.11 manual
Installing software
1. Download latest GDtool binary from products/downloads section of www.granitedevices.fi
Direct link: http://www.granitedevices.fi/pub_files/bin/GDTool.exe
2. un installer with your preferred settings
Introduction to servo system
VSD-A firmware uses closed-loop system with negative feedback.
Closed-loop system (servo system) means that the result (feedback) is subtracted from the
command value, to achieve proper control value so that the command value matches to the
measured value (encoder signal).
Three different control methods can be used with VSD-A:
●Speed servo
●Position servo
●Torque servo
Proportional-integral-derivative controller (PID controller) is used to correct the error between an
command and measured value. Command value is also called as setpoint value.
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Figure 2: Basic control loop

GDtool 0.11 manual
Input value of PID controller is the error value (difference). PID controller uses following formula to
calculate output:
ut=Kp ⋅etKi ⋅
∫et Kd∗de
dt
u, output
e , difference
Kp, gain factor of proportional part
Ki, gain factor of integration part
Kd, gain factor of derivation part
If gain factor are set too high system can become unstable.
Example:
The red line is the target value and black is the real measured output value. In this
case the output starts oscillate. Oscillation causes eventually follow error to occur and
stop the drive, if the boundary value is set properly.
The X axis is time and the Y axis is the encoder count value in position mode. In
velocity mode Y axis equals speed value in encoder counts per PID cycle (400 µs in VSD-
A).
Preferred reading:
Modern Control Systems, by ichard C. Dorf and obert H. Bishop
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Figure 3: Plot, unstable system ith increasing oscillation

GDtool 0.11 manual
Getting started with GDTool
1. Check cable connections and enable logic supply
Warning! Do not enable high voltage supply before setting correct motor parameters!
2. Check that drive's led indicates power
3. Start program from start Programs Granite Devices GDTool→ → →
In current software version, there are 2 option pages:
●Motor pa e contains motor parameters and
current loop configuration.
●Position pa e contains position and velocity
mode parameters.
Description of basic functions
Load to drive button loads parameters to drive and if
Run step response box is checked then the software
commands motor to spin steps box value amount of
steps.
To save configuration permanently to drives memory use
“Save to drive” menu item from Device menu.
To reconnect use connect menu item from Device
menu. You need to reconnect every time after restarting
device!
Note that this version of GDtool does not support
do nloading settings from drive, so every time the
software is started, default settings are restored. It is a
good practice to write down correct values before
closing GDtool.
Warning! Do not press “Load to drive” button if spinning
motor can cause injury.
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Figure 4: GDTool Main indo

GDtool 0.11 manual
Configuring motor parameters
Choose motor page.
First thing is to set motor parameters correct. If you are uncertain about your motor values please
contact to your motor supplier before continuing.
Motor type
Choose motor type. 3 phase brushless motor (AC) or direct current (DC) motor.
AC phasin current (AC only)
This is the current that is driven to AC servo windings at power-up to align rotor. This has
no effect in DC servo mode.
Encoder resolution (counts per revolution)
Sets encoder resolution value to match your motors encoder. This is number of counts in
via 4X decoding, so CP equals 4 times the encoder line or pulse count.
Motor pole count (AC only)
This is the number of magnetic poles in AC servo rotor.
Max peak current
Maximum peak current output value [mA]. This is DC or peak of sine wave value.
Max peak cont. current
Maximum continuous current value [mA]. This is DC or peak of sine wave value.
P ain
Gain factor of proportional part of torque PI-controller
I ain
Gain factor of integration part of torque PI-controller
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Figure 5: Motor settings

GDtool 0.11 manual
1. After adjusting correct settings press “Load and save to drive” button to save values.
2. Drive's red led should be on and green blinking. This is the permanent stop status.
3. Switch power off.
4. Switch on high voltage supply and logic voltage supply
5. To verify your AC motor settings you can use “Test active AC motor confi ” button. If you
experience motor runa ay and follo errors in DC motor mode, you may have wrong polarity of
motor leads. In this case, try swapping the + and – leads of DC motor.
6. Next task is to do current loop tuning. Press “Load to drive” button to test current response with
default settings. Step response window should appear (figure 6). The black line is the target value
and red is the real measured current value. The X axis equals time in PWM cycles (about 55 µs in
VSD-A)
With default values, the current probably doesn't reach the target value so the gains can be
increased.
You can try the following method. First set I- ain to zero, and keep increasing P- ain until current
value reaches the target line (figure 7).
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Figure 6: Plot, current response

GDtool 0.11 manual
Second, start increasing I- ain and decreasing P- ain to get minimal overshoot but still reach
the target
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Figure 7: Current response test plot, P-gain tuning
Figure 8: Plot, properly tuned current loop

GDtool 0.11 manual
7. When finished you can save the configuration to drive by choosing “Save to drive” menu item
from Device menu.
www.granitedevices.fi 10/19 2007-04-27
Figure 9: Save currently active settings to drive