July 2010 20 – 349
20.2.5 Adjusting the electrical offset (drift adjustment)
An offset adjustment is required or recommendable, in case of the following:
You receive the error message EXCESSIVE OFFSET <AXIS>.
The axis drifts.
The servo lag of the axis at standstill is impermissibly high.
You have exchanged the motor.
You have replaced the motor brushes.
You have exchanged the analog servo amplifier.
You have replaced cables or electrical lines on the machine.
You have exchanged the MC.
Offset adjustment
at the analog servo
amplifier
Here are two proposals.
Proposal 1:
8 Set the following machine parameters (note down the original values):
MP 1080.x (integral factor for offset) : 0 (switched off)
MP 1391.x, 1392.x (velocity feedforward control) : 1 (switched on)
MP 7290.x (display step) : 6 (0.1 µm)
8 Switch on the machine. The axis concerned must be in the position control loop.
--> If necessary, ask the machine manufacturer!
8 Select the Programming and Editing operating mode.
8 If open: Close the program management by pressing the END button.
8 Call the code number window.
8 Enter and confirm the code number.
8 End compensation.
The offset adjustment has only to be performed with analog axes.
First the analog servo amplifier is adjusted, subsequently the fine adjustment in the
HEIDENHAIN control is carried out.
Analog servo amplifiers are not HEIDENHAIN products.
Follow the instructions of the servo manufacturer (operating instructions, etc.)!
Pressing the MOD key while the program manager is open calls the interface settings.
Before the adjustment on the servo amplifier, the fine compensation is cancelled via the
control.