Siemens SIMATIC S5 Manual page 270

Torque (
600
500
400
300
200
100
12
Fig. 7/1 Typical torque characteristics of a stepper motor
Note:
If the required torque characteristics can only be achieved in the half step mode
with this motor, then for a given resolution, select a motor with half the step num-
ber. If you remain by the previously selected step number, twice the frequency will
be required to reach the selected speed, since the resolution is halved.
Selecting the power unit
Type
Signal
from 1P
Clock pulse T
T
T
Direction RP
level RP
Reset
pulse RS
The signals listed above are available as 5 V differential signals and as 24 V signals. It is also
possible to use a special voltage between 5 V and 24 V which must be applied externally. The
voltage is set for all axes of the module. The active level (high or low) can be selected separately
in the machine data for each channel.
1000
500
120
Pulse length Signal at
power unit
Voltage
level
1200
(l/rein)
Req. dura-
Required
tion [ins]
level M
Planning
Active level
[high/low]
7 - 3