Siemens SIMATIC FM 353, Manual

Page: 301 / 361

Writing Traversing Programs
10-19
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
Change block on-the-fly - G64 (deceleration)
There are a number of conditions that may delay or prevent a block change on-the-
fly. Here a distinction is necessary between the case in which this type of block
change is suppressed intentionally, and the case in which the selected function
does not permit a block change on-the-fly.
S Block change on-the-fly is suppressed:
− By removing the Enable read-in control signal - this stops program process-
ing at the end of the current block. To continue the program, the enable must
be re-input.
− By output of the M function before or after positioning.
− By M function M0 (stop at end of block). To continue the program, the
START control signal must be reset.
− By a block with a dwell time.
− By processing a program in the Automatic/Single Block mode. Each block
must be activated individually.
− By a change in the acceleration override.
S Functions that themselves prevent block change on-the-fly:
− M functions (during positioning).
1
V
t
M
ÉÉÉ
ÉÉÉ
t
t
2
ÉÉÉÉ
ÉÉÉÉ
t
t
3
M
ÉÉÉÉÉ
ÉÉÉÉÉ
M
V
V
t
1 − Since the M output is completed at the point of deceleration, a block change takes
place on-the-fly.
2 − The M output is not yet complete at the point of deceleration. The axis begins to brake.
At the end of the M output, the axis returns to speed (transition on-the-fly from
deceleration ramp to acceleration ramp).
3 − Axis comes to a complete standstill and waits for the end of M output.