Technology Option F01
08.2012
6SE7087-6QX70 (Version AN) Siemens AG
9-46
Compendium Motion Control
SIMOVERT MASTERDRIVES
An alternative to mechanical alignment of the proximity switch is to use
parameter P188 to define an offset to the measured rotor position. This
has the same effect as mechanical alignment of the proximity switch.
The offset to be entered in P188 is determined as follows:
Step 1:
Perform a homing procedure. If the home position is found,
the rotor position measured at the negative edge of the rough
pulse is output in parameter r189.
Step 2:
The measured value in r189 must be less than -100 % or
greater than +100 %. If the value is outside this range, an
offset must be specified for the rotor position. The offset value
is calculated as follows:
Measured rotor position r189
Offset in P188
Positive, >100 %
No correction necessary
Positive, <100 %
P188 = 200 % - r189
see example in Fig. 9-21
r189 = 20 %
→
P188 = 200 % - 20 % = 180 %
Negative, >-100 %
P188 = -200 % - r189
Example:
r189 = -80 %
P188 = -200 % - (-80 %) = -120 %
Negative, <-100 %
No correction necessary
The graphic below illustrates the procedure.
Rotor position offset
P188 / r189
