Driving Stepper Motors With The Ip; Principle Of Operation Of The Ip 267 - Siemens SIMATIC S5 Manual

IP 267
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Driving Stepper Motors with the IP 267

To aid your understanding of the following chapters, this chapter deals with
some fundamental terms and with the principle of operation of the stepper
motor controller.
2.1

Principle of Operation of the IP 267

The IP 267 generates pulses for the stepper motor power section. The number of
output pulses determines the length of the traversing path and 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 excactly 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 ( 5.6).
To enable the IP 267 to generate these pulse trains, the user must enter the
following data:
• Configuration data; this data describes the individual traverse jobs and the
technical characteristics of the drive system ( 4.1).
• Positioning data; you describe the individual traverse jobs and indicate the
velocities, directions and lengths of the configured paths ( 4.2).
The IP exchanges data with the programmable controller via the serial interface
( Figure 1-1.). During the program scans, all necessary information is sent from
the process output image (PIQ) to the IP 267 in 4-byte long message frames. The
IP 267 cyclically transmits feedback signals on the distance to go and various
status bits to the process input image (PII). See 4.1 to 4.3 for more details.
EWA 4NEB 812 6061-02a

Driving Stepper Motors with the IP 267

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