# Connecting to external tool management

## Tool data

The external tool management system must provide the following data to the CNC when a grinding tool is changed (see [FCT-C10//section Tool data]:

- Type: Tool type 2 for grinding tool
- wear_const: Wear constant
- disc_tilt_angle: Grinding disc tilt angle
- ext_discret_limit: Maximum discrete input by the PLC

When the grinding tool is replaced, the CNC informs the external tool management system of the wear:

The wear data sent includes the following:

- wear_radius, total wear consisting of discrete and continuous wear
- wear_radius_cont, continuous wear

This wear data is generated from the time when the tool is replaced. The values must be taken over by the external tool management and are used internally to recalculate the tool geometric data (radius, length).

## Notice

Unassigned data are assigned the value 0 by default.

Consequence: If the tool type is not assigned Type 2, the error P-ERR-21391 is generated when #OTC ON is programmed.

If grinding_max_infeed is not set, no discrete offset can be applied.

The following also applies: if grinding_wear_const is not set, it is not possible to calculate the continuous offset depending on the path.