Eliminated from:
EVS93xx-EK V8.1, EVS93xx-CK V8.1
Behavior of the new version?
During standstill of the master value, e.g. with velocity = 0 at the
CDATA-DFIN input, the output signal of the y-axis of the
CDATA-NOUT cam profile in the
CDATA function block does not drift any more.
Which products are affected?
EVS93xx-EK V7.1, EVS93xx-CK V7.1
What happens?
Although the master value stands still, e.g. with velocity = 0 at the
CDATA-DFIN input, the output signal of the y-axis of the
CDATA-NOUT cam profile in the
CDATA function block drifts in opposite direction dependent on the parameter setting of the master value-direction of rotation (code C1314/0).
The drift velocity depends on the setting of the 'X0-window' (code C1309).
When does the problem occur?
Since the master value at
CDATA-DFIN varies around 0 the position of the x-axis varies around to the zero crossing of the cam profile if the master position is x = 0.
If the position change exceeds the zero crossing a velocity is indicated at
CDATA-NOUT dependent on the setting made under C1309.
The problem occurs e.g. if a master frequency signal of terminal X9 is
- connected to DATA-DFIN and
- deviates about 0 rpm and
- at the same time the cam profile position is at x = 0.
The downstream configuration usually uses the signal at CDATA-NOUT as speed setpoint for the motor control. It also causes the drive to drift with low speed.
Possible diagnostics?
Diagnostics of the
CDATA-NOUT signal with a downstream integrator (e.g.
PHINT1). The drift shows as increasing position value at the integrator output.
Short-term measures/recommendations?
Avoid speed variations of the
CDATA-DFIN input signal, if necessary switch off the master frequency connection when the drive stands still.
Do not stop the cam drive during the process when the position x = 0 is reached in order to avoid the variation around the zero crossing of the cam profile.
Evaluation:
The problem occurs more often when the machine is initialised or when homing is executed, i.e. the start position of the cam profile function is set to 0 and the master drive stands still.
As soon as the machine is running in the process, the error occurred up to then remains existent and is carried along as static variation over the process.
