Reading the position display

The readout across the top of the screen is where the machine is. It shows two sets of numbers, and knowing which is which saves a great deal of confusion.

Mid-job: work coordinates large on top, machine coordinates beneath, the G54 datum label at the left and the controller state at the right

Work coordinates — where the tool is on your part

WPos is measured from your work zero. This is the coordinate system your programs are written in. If work zero is the front-left corner of your stock at its top surface, then X0 Y0 Z0 is that corner, and Z −5 means five millimetres into the material.

This is the number to watch while cutting. It answers "where is the tool on the workpiece?"

Machine coordinates — where the machine is in itself

MPos is measured from machine zero, established by homing. It does not change when you set a work zero, and it is what the machine's own protections are written in: travel limits, soft limits, tool-change and park positions.

This is the number that answers "can the machine reach that?"

The relationship

Setting work zero does not move the machine. It records the distance between the two origins — the work offset. Machine coordinates stay exactly as they were; work coordinates are re-based around the point you chose.

Other fields

At rest — the state chip reads Idle, and the datum label shows which system the work numbers are measured in

State — what the controller is doing: Idle, Run, Hold, Alarm.

Feed — the current feed rate, with your override percentage beside it while a job runs.

Spindle — spindle speed as reported by the controller.

The datum label — the work numbers are labelled with the work coordinate system they are measured in, G54 through G59, read from the controller. A +G92 beside it means a temporary offset is stacked on top of that system. Before the controller has said which system is live, the label falls back to WPOS.