Siemens SINUMERIK 840C Installation Instructions Manual page 818

11.92
0°
Example
Actual position:
Actual rotation:
Programmed position:
Nearest position at which spindle
can be stopped:
Distance to be traversed in addition
to the deceleration distance:
Total distance to be traversed:
Example for case 1b
2. Spindle not in synchronism with zero mark
In this case, neither the actual position nor the distance to be traversed can be ascertained
correctly.
Therefore, the spindle is first driven at creep speed (MD 427* to 434*) until the zero mark
of the encoder is recognized.
This allows the internal actual-value counter to be synchronized with the encoder. The
remainder of the positioning sequence is identical to that of case 1b.
If, when M19 is selected, the spindle rotates at a speed above the encoder cutoff
frequency (MD 462*), the spindle is first decelerated under control to the creep speed.
If the speed of the spindle is below the limit speed, it must be resynchronized. Continue
then as in case 1b).
© Siemens AG 1992 All Rights Reserved
SINUMERIK 840C (IA)
315°
positive
90°
270°
+180°
+495°
6FC5197- AA50
12 Functional Descriptions
12.7.2 Description of the spindle modes
12–43