MCV_BlockSearchCtrl
This function block is used to inform the PLC of block search status.
Enable:
- Set “Enable” input to TRUE
- "Valid" output displays TRUE
Once the block is enabled by the PLC; the motion controller (MC) signals the state of the blocks search at the outputs of the FB.
The “Selected” output indicates whether the MC was configured for block search. The next time an NC program is started, no axis motion takes place until the continuation position is found.
All "Wait…” outputs reflect the block search state in the MC.
The PLC sends an acknowledgement over the “AckStart” input to indicate that it was informed by the “WaitAckStart” signal that the MC will start the NC program in block search mode after the PLC has completed the necessary measures, e.g. suppress hardware reaction after the MC outputs technology functions.
The “AckFinished” input is used by the PLC to acknowledge the “WaitAckFinished” output signal, e.g. after hardware reactions are re-enabled after the output of technology functions.
The "WaitReturnToPath" and "WaitPathContinue" output signals are acknowledged by restarting the NC program, e.g. by confirming the START button in an HMI.
Block diagram
FB parameters
VAR_IN_OUT | ||
Variable name | Data type | Description |
AxesGroup | AXES_GROUP_REF | Axis group reference |
VAR_INPUT | ||
Variable name | Data type | Description |
Enable | BOOL | If “Enable” is TRUE, the PLC is registered for the block search interface and the MC signals the state of block search over the "Wait…” outputs. The MC then waits for the PLC to acknowledge the block search states signalled. |
AckStart | BOOL | The output signal "WaitAckStart” is acknowledged on the rising edge. This is how the PLC indicates that it has completed its preparations for block search and the MC can start to find the continuation position. |
AckFinished | BOOL | The output signal "WaitAckFinished” is acknowledged on the rising edge. This is how the PLC indicates that it has received the finished message that the continuation position was found and its preparations are completed so that real axis motions can finally be resumed. |
VAR_OUTPUT | ||
Variable name | Data type | Description |
Valid | BOOL | When this output is TRUE, the function block outputs indicate the block search state. |
WaitAckStart | BOOL | If the output is TRUE, an NC program was started in block search mode and the MC waits for acknowledgement from the PLC at the “AckStart” input before searching for the continuation position which was previously configured by one of the FBs MCV_BlockSearchSetBlockCount or MCV_BlockSearchSetBlockNumber or MCV_BlockSearchFileOffset. |
WaitAckFinished | BOOL | If the output is TRUE, the continuation position was found in the NC program and the MC waits for acknowledgement from the PLC at the “AckFinished” input. Up to this point no real axis motion takes place. |
WaitReturnToPath | BOOL | This output is TRUE once the PLC signals via “AckFinished” that the PLC has completed the preparations to permit the execution of real axis motions. This is the signal for the user to execute an action to move the axes to the continuation position if they are not already at this position. Normally this takes place by pressing the START button in the HMI. Note: The start movement then takes place directly. |
WaitPathContinue | BOOL | TRUE at this output indicates that the axes are located at the continuation position within the permitted deviation. After the ensuring enable, the NC program executes real axis motions starting at the continuation position. Enable normally takes place by pressing the START button in the HMI. The permitted deviation was already defined when block search was configured by the "Deviation" input in the FB MCV_BlockSearchSetBlockCount or MCV_BlockSearchSetBlockNumber or MCV_BlockSearchFileOffset. |
Selected | BOOL | TRUE indicates that block search was selected by FB MCV_BlockSearchSetBlockCount or MCV_BlockSearchSetBlockNumber or MCV_BlockSearchFileOffset. As a result no real axis motion takes place the next time an NC program is started until a continuation position was found. |
Error | BOOL | TRUE indicates that an error occurred |
ErrorID | WORD | Error identifier |