MLPmpRel

 Function - Used to perform two subsequent relative moves.

Inputs

Input	Data Type	Range	Unit	Default	Description
BlockID	DINT	-2147483648 to 2147483647	N/A	No default	ID name of a PMP function block in the Pipe Network.
DeltaFirst	LREAL	No range	User units	No default	Length of the first move. The value is entered in the FIRST_TRAVEL_SPEED field in the Parameter tab.
DeltaSecond	LREAL	No range	User units	No default	Length of the second (return) move. The value is entered in the LAST_TRAVEL_SPEED field in the Parameter tab.

Outputs

Output	Data Type	Range	Unit	Description
Default (.Q)	BOOL	FALSE, TRUE	N/A	Returns TRUE if the function or function block successfully completed. See Function - General Rules.

Remarks

• Using the MLPmpRel function block, the PMP Generator produces forward-backward motions with a non-stop, jerk-free transition through zero speed.
  • See the example image PMP Generator Forward and Backward Motion Profile.
  • This feature is useful for linear axes which must move back and forward without any pause at one end.
• This function is used to do a single relative move, ending in zero speed, by setting the DeltaSecond argument to zero (0.0).
  • If it is done, for the controlling speed to be the first move, the Last_Travel_Speed parameter must be set equal to or greater than the First_Travel_Speed parameter.
• The slower of the two speeds is utilized to optimize the S-curve behavior for the move whether it is a 2 or 1 delta move.
• If the DeltaSecond argument is non-zero, it must have the opposite sign than the sign of the DeltaFirst argument.

Figure 1: PMP Generator Forward and Backward Motion Profile

FBD Language Example

FFLD Language Example

IL Language Example

Not available.

ST Language Example

//Execute a Relative move on a PMP Block name “PmpMaster” with a First Travel Speed of 750.0, Second Travel Speed of -500,
MLPmpRel( PipeNetwork.PmpMaster, 750 , -500);

See Also

• MLPmpWriteAccel
• MLPmpWriteFstSpd
• MLPmpWriteJerk
• MLPmpWriteLstSpd