Siemens SINAMICS S120 Function Manual page 270

Extended Functions
Function module "basic positioner"
Description
The function direct setpoint input allows positioning (absolute, relative) and setting
up (endless, position controlled) using direct setpoint inputs (e.g. via the PLC using
process data).
Further, during traversing motion, it is possible to influence motion parameters
(flying setpoint transfer); it is also possible to make a flying change between the
setting-up and positioning modes.
The mode direct setpoint input (MDI) can also be used if the axis is not referenced
in the setting-up or relative positioning modes, so that using "flying referencing"
(refer to the separate section), flying synchronization and post-referencing are pos-
sible.
The function direct setpoint input is activated using p2647 = 1. A differentiation is
made between two modes – the mode positioning (p2653 = 0) and the mode
setting-up (p2653 = 1).
In the positioning mode, using parameters (position, velocity, acceleration and de-
celeration) absolute (p2648 = 1) or relative (p2648 = 0) positioning can be carried
out.
In the setting-up mode, using parameters (velocity, acceleration and deceleration)
"endless" closed-loop position control behavior can be carried-out.
It is possible to make a flying changeover between the two modes.
When continuous transfer (p2649 = 1) is activated, changes to the MDI parameters
are immediately accepted. Otherwise, the values are only accepted after a positive
signal edge at binector input p2650 (setpoint transfer edge).
The positioning direction can be specified using p2651 (positive direction) and
p2652 (negative direction). If both inputs have the same state, then for absolute
positioning (p2648 = "1") modulo axes (p2577 = "1") are moved through the
shortest distance.
4-270
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition