Siemens simatic et 200s Operating Instructions Manual page 28

1STEP 5V/204kHz
2.5 Fundamentals of Positioning
Acceleration/delay a
The maximum permitted acceleration/delay depends on the load to be moved.
The motor must reach a torque high enough to accelerate or delay the load without loss of
step.
Depending on the application, you must also take into account additional criteria for setting
the acceleration/delay, such as smooth starting and stopping.
Setting the Acceleration/Delay a
Through parameter assignment, the 1STEP 5V/204kHz permits the acceleration/delay to be
set in steps by means of the multiplier i.
During the acceleration phase, the frequency is increased in steps starting from the
start-stop frequency F
The time interval for the gradual increase in frequency can be set in steps. To do this, select
the multiplier i between 1 and 255, which is multiplied with the fixed period of 0.032 ms. After
each time interval, the frequency is increased by one quarter of the base frequency F
In the delay phase, the output frequency is reduced in the same way.
You can lower the acceleration/delay a again with the reduction factor R (1 or 0.1) in the
positioning job.
a = F
Reduction factor R=1
Reduction factor R=0.1
See also
Setting the Base Frequency (Page 29)
28
until the output frequency F
ss
R / (i 0.128 ms)
b * *
has been reached.
a
Min. a
0.12 Hz/ms
0.012 Hz/ms
Operating Instructions, 05/2007, A5E00124871-04
b
Max. a
6250 Hz/ms
625 Hz/ms
ET 200S Positioning
.