Siemens SINUMERIK 840C - Manual (Page 749)

09.95 10 Axis and Spindle Installation
10.5.3 Positioning mode, M19, M19 through several revolutions
Example for case 1b
0°
Example
Actual position: 315°
Actual rotation: positive
Programmed position: 90°
Nearest position at which spindle
can be stopped:
270°
Distance to be traversed in addition
to the deceleration distance:
+180°
Total distance to be traversed: +495°
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).
Speed characteristic for case 2
n
t
Creep speed for M19
Recognition of zero mark
© Siemens AG 1992 All Rights Reserved 6FC5197- AA50 10–59
SINUMERIK 840C (IA)