Direct Setpoint Input (Mdi) - Siemens SINAMICS S120 Function Manual

Function modules
7.9 Basic positioner
7.9.6

Direct setpoint input (MDI)

Features
● Select direct setpoint input (p2647)
● Select positioning type (p2648)
● Direction selection (p2651, p2652)
● Setting-up (p2653)
● Fixed setpoints
● Connector inputs
– CI: Velocity override (p2646)
● Accept (p2649, p2650)
Description
The direct setpoint input function allows for positioning (absolute, relative) and setup
(endless position-controlled) by means of direct setpoint input (e.g. via the PLC using
process data).
During traversing, the motion parameters can also be influenced (on-the-fly setpoint
acceptance) and an on-the-fly change can be undertaken between the Setup and Positioning
modes. The "direct setpoint input" mode (MDI) can also be used if the axis is not referenced
in the "setup" or "relative positioning" modes, which means that "flying referencing" (see the
separate section), flying synchronization, and post-referencing are possible.
The direct setpoint input function is activated by p2647 = 1. A distinction is made between
two modes: positioning mode (p2653 = 0) and setup mode (p2653 = 1).
In "positioning" mode, the parameters (position, velocity, acceleration and deceleration) can
be used to carry out absolute (p2648 = 1) or relative (p2648 = 0) positioning with the
parameter p2690 (fixed setpoint position).
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.
If continuous acceptance (p2649 = 1) is activated, changes to the MDI parameters are
accepted immediately. Otherwise the values are only accepted when there is a positive edge
at binector input p2650 (setpoint acceptance edge).
276
– CO: Position setpoint (p2690)
– CO: Velocity setpoint (p2691)
– CO: Acceleration override (p2692)
– CO: Deceleration override (p2693)
– CI: MDI position setpoint (p2642)
– CI: MDI velocity setpoint (p2643)
– CI: MDI acceleration override (p2644)
– CI: MDI deceleration override (p2645)
Function Manual, (FH1), 07/2007 Edition, 6SL3097-2AB00-0BP4
Drive Functions