Relative Positioning (Mode 4) - Siemens simatic et 200s Operating Instructions Manual

1PosSSI/Analog
6.6 Functions of the 1PosSSI/Analog
6.6.7

Relative Positioning (MODE 4)

Definition
In relative positioning the 1PosSSI/Analog moves the drive from the start position in a
specified direction for a certain preset distance.
Supply the control interface with the distance to be traveled, and start MODE 4, specifying
the direction (DIR_M or DIR_P). The 1PosSSI/Analog moves the drive towards the
destination for a certain distance with the set voltage for rapid feed. At the switchover point,
the 1PosSSI/Analog switches from rapid to creep feed. At the switch-off point, the
1PosSSI/Analog completes the run either directly or via the ramp depending on the
parameter assignment.
If you start during a current run, the 1PosSSI/Analog executes any required change in
direction using deceleration or acceleration.
The preset distance is not checked by the 1PosSSI/Analog. This means that more than one
revolution may be involved with rotary axes.
Figure 6-14
270
Execution of Relative Positioning
Operating Instructions, 05/2007, A5E00124871-04
ET 200S Positioning