Siemens SIMATIC S5-100U System Manual page 474

Function Modules
Because of its performance capability and the complexity of its description, the IP 267 has its own
manual that you can order separately. The order number is: 6ES5 998-5SD21. The IP 267 Stepper
Motor Control Module expands the field of application as an intelligent I/O module (IP) of the
S5-100U and S5-95U programmable controllers for "closed-loop control positioning". The IP 267
controls positioning processes independently of the run time of user programs in the programmable
controller. The CPU is not loaded with processing positioning job operations.
You can plug the IP 267 into slots 0 to 7 in the programmable controller. It then occupies addresses
in the analog address area of the programmable controller.
Principle of Operation
The IP 267 generates pulses for the stepper motor power section. The number of output pulses
determines the length of the traversing path. The pulse frequency is a measure of the velocity.
Each pulse causes the stepper motor shaft to turn through a certain angle. In the case of
high-speed pulse trains, this step movement becomes a constant rotational movement. Stepper
motors can reproduce all movement sequences only as long as no steps are lost. Step losses can
be caused when load variations occur or when the programmed pulse trains exceed motor-specific
values.
To enable the IP 267 to generate these pulse trains, the user must enter the following data:
• Configuration data: This data describes the individual stepper motors and the technical charac-
teristics of the drive system.
• Positioning data: This data describes the individual traverse jobs and indicates the velocities,
directions, and lengths of the configured paths.
The IP exchanges data with the programmable controller via the serial interface. During the program
scans, all necessary information is sent from the process image output table (PIQ) to the IP 267 in
4-byte messages. The IP 267 cyclically transmits feedback signals on the remaining distance to go
and various status bits to the process image input table (PII).
Using the configuration and positioning data settings, the IP 267 generates a symmetrical traverse
profile consisting of an acceleration ramp, a constant velocity range, and a deceleration ramp.
f
f
A
f ss
1. Accelera- 2. Constant stepping
tion ramp
f ss = Start/stop rate; f = Stepping rate
A
15-60
3. Decelera-
rate/velocity range
Figure 15-29. Velocity Profile of the IP 267
tion ramp
t
S5-100U
EWA 4NEB 812 6120-02b