Mc_Home Instruction - Siemens SIMATIC S7-1200 Manual

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10.4 MC_Home instruction

10.4 MC_Home instruction
Table 10- 8 MC_Home instruction
LAD / FBD
STEP 7 automatically creates the DB when you insert the instruction.
1
In the SCL example, "MC_Home_DB" is the name of the instance DB.
2
The following types of homing are available:
● Direct homing absolute (Mode = 0): The current axis position is set to the value of
● Direct homing relative (Mode = 1): The current axis position is offset by the value of
● Passive homing (Mode = 2): During passive homing, the MC_Home instruction does not
● Active homing (Mode = 3): The homing procedure is executed automatically.
Table 10- 9 Parameters for the MC_Home instruction
Parameter and type
Axis
Execute
Position
198
SCL
"MC_Home_DB"(
Axis:=_multi_fb_in_,
Execute:=_bool_in_,
Position:=_real_in_,
Mode:=_int_in_,
Done=>_bool_out_,
Busy=>_bool_out_,
CommandAborted=>_bool_out_,
Error=>_bool_out_,
ErrorID=>_word_out_,
ErrorInfo=>_word_out_);
parameter "Position".
parameter "Position".
carry out any homing motion. The traversing motion required for this step must be
implemented by the user via other motion control instructions. When the reference point
switch is detected, the axis is homed.
Data type
IN TO_Axis_PTO
IN Bool
IN Real
Description
Use the MC_Home instruction to match
the axis coordinates to the real, physical
drive position. Homing is required for
absolute positioning of the axis:
In order to use the MC_Home instruction,
the axis must first be enabled.
Description
Axis technology object
Start of the task with a positive edge
Mode = 0, 2, and 3 (Absolute position of axis after

completion of the homing operation)
Mode = 1 (Correction value for the current axis position)

Limit values: -1.0e ≤ Position ≤ 1.0e
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Easy Book
Manual, 11/2011, A5E02486774-04