User Manual

TMCM-102 Manual (V1.01 / 7 November 2007) 16
Copyright © 2006, TRINAMIC Motion Control GmbH & Co. KG
right after the StallGuard profiler has been selected in the “Setup” menu. After this has been
successfully checked the StallGuard profiler window will be shown.
First, select the axis that is to be used. Then, enter the “Start
velocity” and the “End velocity”. The start velocity is used at
the beginning of the profile recording. The recording ends
when the end velocity has been reached. Start velocity and
end velocity must not be equal. After you have entered these
parameters, click the “Start” button to start the StallGuard
profile recording. Depending on the range between start and
end velocity this can take several minutes, as the load value
for every velocity value is measured ten times. The “Actual
velocity” value shows the velocity that is currently being
tested and so tells you the progress of the profile recording.
You can also abort a profile recording by clicking the “Abort”
button.
The result can also be exported to Excel or to a text file by
using the “Export” button.
Figure 5.6: The StallGuard Profiler
5.8.2.1 The result of the StallGuard profiler
The result is shown as a graphic in the StallGuard profiler window. After the profile recording has
finished you can scroll through the profile graphic using the scroll bar below it. The scale on the
vertical axis shows the load value: a higher value means a higher load. The scale on the horizontal
axis is the velocity scale. The colour of each line shows the standard deviation of the ten load values
that have been measured for the velocity at that point. This is an indicator for the vibration of the
motor at the given velocity. There are three colours used:
• Green: The standard deviation is very low or zero. This means that there is effectively no vibration
at this velocity.
• Yellow: This colour means that there might be some low vibration at this velocity.
• Red: The red colour means that there is high vibration at that velocity.
5.8.2.2 Interpreting the result
In order to make effective use of the StallGuard feature you should choose a velocity where the load
value is as low as possible and where the colour is green. The very best velocity values are those
where the load value is zero (areas that do not show any green, yellow or red line). Velocities shown
in yellow can also be used, but with care as they might cause problems (maybe the motor stops even
if it is not stalled).
Velocities shown in red should not be chosen. Because of vibration the load value is often
unpredictable and so not usable to produce good results when using stall detection.
As it is very seldom that exactly the same result is produced when recording a profile with the same
parameters a second time, always two or more profiles should be recorded and compared against
each other.
5.9 Environment Temperature Considerations
As the power dissipation of the MOSFETs is very low, no heat sink or cooling fan is needed, unless
environment temperature is raised and the module continuously is operated at a high current.
When the output bridge temperature reaches a critical value, the output current is reduced by 20%. If
the temperature still rises higher, the outputs become switched off. The coils are automatically
switched on again when the temperature is within the limits again. An optional cooling fan can be
mounted to cope with higher environment temperatures, when problems are perceived. The 5V power
supply output can be used to operate a small fan.