User manual

Brick Controller User Manual
Drive-Motor Setup 149
The open-loop test is usually performed
on an unloaded motor. The open loop
command output is adjustable, start off
with a conservative 1 to 2 percent
command output (i.e. #nO2) value and
increment gradually until you see a
satisfactory result.
If the failure persists (inverted saw tooth,
as shown in the plot), or you observe
oscillations in the response instead of a
saw tooth, then most likely the direction
sense of the encoder is opposite to the
command output.
Unsatisfactory Open Loop Test Result
General recommendation for troubleshooting an unsuccessful open loop test
An inverted saw tooth response, most times, indicates that the direction sense of the encoder is opposite to
that of the command output.
 Quadrature | Sinusoidal:
Change I7mn0 to 3 from 7 (default) or vice-versa.
 HiperFace:
HiperFace encoders send absolute encoder data on power-up. If the on-going position direction is
reversed, one needs to make sure that the absolute data sent on power-up agrees with the new
direction of the encoder.
 Resolver:
Change the direction from clock wise to counter clock wise in the first encoder conversion table
entry (see resolver feedback setup section).
 Absolute Serial Encoders (EnDat, SSI, BiSS, Yaskawa, Panasonic, Tamagawa):
The Brick Controller has no control on the direction sense of the serial data stream (packets).
There are no software parameters that allow changing the direction sense of absolute serial
encoders. Normally, it is set by jumpers or software at the encoder side.
Some amplifiers allow swapping the DAC+ and DAC- signal to invert the direction travel of the
motor. Otherwise, two of the motor leads have to be swapped.
If the motor/axis direction does not comply now with the machine design then negative jog
commands can be issued for positive motion, and vice versa. Similarly, for motion programs, the
motor can then assigned to a negative axis definition.