102BTechnology instructions
9.3 Basic motion control
S7-1200 Programmable controller
356
System Manual, 11/2011, A5E02486680-05
9.3.2.6
MC_MoveRelative instruction
Table 9- 35 MC_MoveRelative instruction
LAD / FBD
SCL
Description
"MC_MoveRelative_DB"(
Axis:=_multi_fb_in_,
Execute:=_bool_in_,
Distance:=_real_in_,
Velocity:=_real_in_,
Done=>_bool_out_,
Busy=>_bool_out_,
CommandAborted=>_bool_out_,
Error=>_bool_out_,
ErrorID=>_word_out_,
ErrorInfo=>_word_out_);
Use the MC_MoveRelative
instruction to start a positioning
motion relative to the start position.
In order to use the
MC_MoveRelative instruction, the
axis must first be enabled.
1
STEP 7 automatically creates the DB when you insert the instruction.
2
In the SCL example, "MC_MoveRelative_DB" is the name of the instance DB.
Table 9- 36 Parameters for the MC_MoveRelative instruction
Parameter and type
Data type
Description
Axis
IN
TO_Axis_1
Axis technology object
Execute
IN
Bool
Start of the task with a positive edge (Default value: False)
Distance
IN
Real
Travel distance for the positioning operation (Default value: 0.0)
Limit values: -1.0e
12
≤ Distance ≤ 1.0e
12
Velocity
IN
Real
Velocity of axis (Default value: 10.0)
This velocity is not always reached on account of the configured
acceleration and deceleration and the distance to be traveled.
Limit values: Start/stop velocity ≤ Velocity ≤ maximum velocity
Done
OUT
Bool
TRUE = Target position reached
Busy
OUT
Bool
TRUE = The task is being executed.
CommandAborted
OUT
Bool
TRUE = During execution the task was aborted by another task.
Error
OUT
Bool
TRUE = An error has occurred during execution of the task. The
cause of the error can be found in parameters "ErrorID" and
"ErrorInfo".
ErrorID
OUT
Word
Error ID for parameter "Error" (Default value: 0000)
ErrorInfo
OUT
Word
Error info ID for parameter "ErrorID" (Default value: 0000)