Distance control
Commanding distance control | |
Description | This control unit can influence the distance control of the axis. This is dependent on whether the distance control function is selected in the axis parameters (see P-AXIS-00328). |
Data type | MC_CONTROL_DISTANCE_CONTROL, see description of Control unit with usage check |
Access | PLC reads state_r and writes command_w + enable_w |
ST path | gpAx[axis_idx]^.lr_mc_control.distance_control |
Flow control of commanded values | |
ST element | .command_semaphor_rw |
Signal flow | PLC → CNC |
Data type | BOOL |
Peculiarities | Consumption data item |
Access | CNC accepts the commanded values when this element has the value TRUE. After successful acceptance the CNC sets this value to FALSE. PLC sets this value to TRUE when the commanded value is enabled for acceptance by the CNC. The commanded values can only be updated by the PLC if this element has the value FALSE. |
Commanded values | |
ST element | .command_w |
Signal flow | PLC → CNC |
Data type | |
Access | PLC writes |
Distance control state | |
ST element | .state_r |
Signal flow | CNC → PLC |
Data type | |
Access | PLC is reading |
Redirection | |
ST element | .enable_w |
Command for distance control | ||
Description | This entry commands distance control. | |
Signal flow | PLC → CNC | |
Data type | HLI_DISTANCE_CONTROL_COMMAND | |
ST Path | gpAx[axis_idx]^.lr_mc_control.distance_control.command_w | |
Access | PLC writes | |
Elements of the data type | ||
ST element | .transition | |
Data type | UDINT | |
Value range/Description | See Table - Permissible transitions to command distance control | |
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ST element | .position | |
Data type | DINT | |
Value range | [DINT_MIN, DINT_MAX] | |
Description | The meaning depends on the commanded transition: HLI_DIST_CTRL_ON: Command position of the workpiece surface (SET_POS) HLI_DIST_CTRL_REF: Reference position of the workpiece surface (REF_POS) | |
Distance control state | |
Description | This entry reads the distance control state. |
Signal flow | PLC → CNC |
Data type | HLI_DISTANCE_CONTROL_STATE |
ST Path | gpAx[axis_idx]^.lr_mc_control.distance_control.state_r |
Access | PLC is reading |
Elements of the data type | |
Element | .actual_state |
Data type | UDINT |
Access | PLC is reading |
Value range/Description | See table: Distance control |
Element | .actual_position |
Data type | DINT |
Unit | 0.1 µm or 0.0001° |
Access | PLC reads |
Description | This data item indicates the current actual position of the workpiece surface detected by the sensing controller. |
Characteristics | This data item is entered only if distance control is activated in the axis parameters (see P-AXIS-00328). |
Element | .actual_offset |
Data type | DINT |
Unit | 0.1 µm or 0.0001° |
Access | PLC reads |
Description | This data item indicates the current position offset of distance control by which the axis was moved due to deviations between the actual workpiece surface and the specified position (SET_POS). The following applies in stationary state (constant workpiece surface and position offset completely run out): Position offset = SET_POS – actual_position |
Characteristics | This data item is entered only if distance control is activated in the axis parameters (see P-AXIS-00328). |
Tables for commanding distance control
The tables below list the permissible values to command distance control and the defined states resulting.
Permissible transitions to command the distance control
Transition | Value | Meaning |
HLI_DIST_CTRL_OFF | 0 | Distance control is deactivated. The program switches to the TURNING OFF state in which the position offset is run out. The state then switches automatically to the INACTIVE state. |
HLI_DIST_CTRL_ON | 1 | Distance control is activated. When activated a command position for the workpiece surface must be transferred in the “position” datum. If no absolute encoder is used, distance control must first be referenced. |
HLI_DIST_CTRL_FREEZE | 2 | The current position offset is frozen. Axis adjustment to the actual workpiece surface is ended. |
HLI_DIST_CTRL_REF | 3 | Referencing distance control if no absolute encoder is used. Referencing is only permitted in the INACTIVE state. With this transition a reference position must additionally transferred in the “position” datum. |
HLI_DIST_CTRL_ON_CONST_DIST | 4 | Activating distance control with continuous distance specification. On activation, a set position must be specified. If the distance sensor supplies no absolute values, distance control must be referenced in advance. |
HLI_DIST_CTRL_DRYRUN | 5 | Activate distance control for pure evaluation of data. No axis tracking in case of changes to the workpiece surface. When activated a command position for the workpiece surface must be transferred in the “position” datum. If no absolute encoder is used, distance control must first be referenced. |
HLI_DIST_CTRL_CONST_DIST | 6 | Activate distance control for pure evaluation of data. No axis tracking in case of changes to the workpiece surface. On activation, a set position must be specified. If the distance sensor supplies no absolute values, distance control must be referenced in advance. |
Defined states of distance control
State | Value | Meaning |
HLI_DIST_CTRL_STATE_INACTIVE | 0 | Distance control is deactivated. The specified offset (“actual_offset”) is 0. |
HLI_DIST_CTRL_STATE_ACTIVE | 1 | Distance control is active and adjusts the axis to the workpiece surface. |
HLI_DIST_CTRL_STATE_FREEZE | 2 | Distance control is active. The offset (“actual_offset”) is frozen, i.e. the axis is not adjusted to the workpiece surface. |
HLI_DIST_CTRL_STATE_TURNING_OFF | 3 | Distance control was deactivated. The actual active offset (“actual_offset”) is run out. As soon as the offset is 0, an automatic switch to INACTIVE state takes place. |
HLI_DIST_CTRL_STATE_ACTIVE_CONST_DIST | 4 | Distance control is active and adjusts the axis to the workpiece surface. Continuous specification of the set distance of the tool to the workpiece surface. |
HLI_DIST_CTRL_STATE_ERROR | 5 | Distance control is in error state, e.g. due to an incorrect state transition or due to an error in the position controller. Only a transition to TURNING OFF is possible to exit this state. |
HLI_DIST_CTRL_STATE_DRYRUN_CONST_DIST | 6 | Distance control is active, however axis is not adjusted to workpiece surface. This allows the evaluation of data, for example filter effect without feedback from the control system. Continuous commanding of the set distance of the tool to the workpiece surface. |
HLI_DIST_CTRL_STATE_DRYRUN_SETPOS | 7 | Distance control is active, however axis is not adjusted to workpiece surface. This allows the evaluation of data, for example filter effect without feedback from the control system. |