Technical data

Technology functions
CPU 317T: Technology Functions
A5E00251798-03
6-33
Data record changeover time
The data record changeover time is determined by the configuration variable
TypeOfAxis.NumberOfDataSets.changeMode. The variable can assume the values
listed below:
• NEVER:
Data record changeover not allowed. "MC_ChangeDataset" is canceled with
error (ErrorID = 8045).
• IN_POSITION: (default setting in S7T Config after insertion of an axis)
The data record is changed when the configured positioning window of the
active motion is reached.
• IN_STANDSTILL:
The data record is changed when the standstill signal of the relevant axis is
reached. The data record is changed immediately after the axis has reached
standstill.
• IMMEDIATELY
The data record is changed immediately.
You can modify this response in the expert list of S7T Config. You could also edit
the configuration variable at the technology function "MC_WriteParameter."
Warning
A different gear ratio setting in the data record changeover configuration may
cause a jerk at the axis, regardless whether the axis is at a standstill or not
Hence, make sure that the drive is not enabled for position control.
Encoder calibration
If the encoder of the current data record and the new encoder do not match, an
encoder calibration is performed based on input parameter SyncEncoder. The
encoder calibrating function assigns the actual position value of the overridden
encoder to the new encoder. After calibration, the function changes the data
record.
Both encoders must operate at the same speed in order to ensure their precise
calibration. A precise integration into the active process can not be ensured if any
slip between the encoders is detected, or if one of the encoders is idle. Within the
time expiring between encoder calibration and data record changeover, this would
lead to the development of a difference in encoder values which can not be
aligned.
Encoder calibration is repeated cyclically if the data record can not be changed
immediately.
Warning
When you change the encoder alongside with the data record and do not calibrate
the encoder, the axis may perform a compensating movement as a result of the
different encoder positions.