MLPmpRel
Description
This function is used to perform two subsequent relative moves. Using the MLPmpRel function block, the PMP Generator is capable of producing forward-backward motions with a non-stop, jerkIn physics, jerk is the rate of change of acceleration; more precisely, the derivative of acceleration with respect to time-free transition through zero speed (see Figure below). This feature is frequently useful for linear axes which must move back and forward without any pause at one end.
This function can also be 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 has to be set equal to or greater than the “First_Travel_Speed” parameter.
In general, 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 7-105: PMP Generator Forward & Backward Motion Profile
Arguments
Input
BlockID | Description | ID Name of the PMP function block in the Pipe Network |
Data type | DINT | |
Range | [-2147483648, 2147483648] | |
Unit | N/A | |
Default | — | |
DeltaFirst | Description | Length of first Move |
Data type | LREAL | |
Range | — | |
Unit | User unit | |
Default | Value defined in the setup of a PMP Block within a Pipe Network. It is the “FIRST_TRAVEL_SPEED” field in the parameter tab. | |
DeltaSecond | Description | Length of second (return) Move |
Data type | LREAL | |
Range | — | |
Unit | User unit | |
Default | Value defined in the setup of a PMP Block within a Pipe Network. It is the “LAST_TRAVEL_SPEED” field in the parameter tab. |
Output
Default (.Q) |
Description | Returns True if the MLPmlRel successfully completed See more details here. |
Data type | BOOL | |
Unit | N/A |
Related Functions
Example
Structured Text
//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);
Ladder Diagram
Function Block Diagram