# Description of elements in the BlockSearch_Common visualisation

Key: “PLC code handles block search" / "Block search by visu input”

Only one of the two keys can be active.

After the PLC application starts, the pre-assigned key "Block search by visu input" and the control unit are enabled on the HLI for the block search (enable_w of the control unit is TRUE). This is indicated by the green indicator "EnableW" in the "Block search handshake CH1" panel in the section below the two keys.

When "PLC code handles block search" is activated, all the handshakes required are processed by the state machine which is implemented at the end in the POU BlockSearch (program) after block search is parameterised and the NC program is started .

## General block search parameters

Parameter | Description | Unit
Type | Block search type |
covered distance | Specifies the distance moved in an NC block | 0/00
dist. from prg st. | Distance moved since program start or since the last occurrence of the NC command #DISTANCE PROG START CLEAR and activation of the calculation by #DISTANCE PROG START ON. | 0.1 µm
Deviation | maximum deviation of the axes between actual position and continue position when processing is resumed after block search | 0.1 µm
axes move bp | Specifies an automatic interrupt point by specifying the distance to program start | 0.1 µm