# PLC interface (status information of a channel)

At present, there is no channel-specific control unit for 3D distance control since the NC program currently handles control:

The following value are displayed on the HLI (PLC interface) so that the PLC can adapt the focus point or normalise the sensor:

- tool inclination angle α
- current (virtually extended) tool length; this means the distance between the laser exit point and laser focus point

Link to PLC

Virtual tool length
Description | Virtual too length This length consists of the actual length of the tool and the extension caused by monitoring the inclination angle.
Signal flow | CNC → PLC
ST path | gpCh[channel_idx]^.bahn_state.virt_tool_length_r
Data type | DINT
Unit | 0.1 µm
Access | PLC reads
Special feature | If, in addition to kinematic transformation, collision avoidance is activated by the 2nd kinematic step 98, the adapted tool length (virtual tool length) is displayed. This avoids the tool head from approaching any closer to the workpiece. This length corresponds to the actual distance between the laser exit and the laser focus point on the workpiece.

Tool inclination angle
Description | Current inclination angle of the tool.
Signal flow | CNC → PLC
ST path | gpCh[channel_idx]^.bahn_state.inclination_r
Data type | DINT
Unit | 0.0001 °
Access | PLC reads
Special feature | If, in addition to kinematic transformation, collision avoidance is activated by the 2nd kinematic step 98, the current inclination angle is displayed.