Making a surface grinder with no controller measurable

Most monitoring products start with the controller. This machine has none to speak of — a manual surface grinder with a spindle switch. Machines like this stay invisible in a plant's figures: no controller data, no counters, no state.

A Ziersch surface grinder in the laboratory, used for surface grinding. We installed an EdgeBox at the machine and added sensors: one that measures the current the spindle draws, and three more for the grinding process itself.

• The spindle's current draw, recorded in full detail.
• Three process sensors at the machine.
• No controller data of any kind.

From the spindle's current draw, Toleron tells three states apart: off, idle and running. We calibrated this once against the machine's real levels. Until then the machine showed Not Calibrated instead of a colour; since then every dashboard marks the state as derived from current draw, so nobody mistakes it for controller data.

A built-in self-test checked the sensors before they were used. After that, the machine joined the shift calendar and downtime tracking like any machine with a controller.

• Machine state (off / idle / running) on the shift board and in the timelines, clearly marked as derived from current draw.
• Utilisation per shift without a single controller signal.
• Downtime taken from the state history, classifiable in bulk.
• The three process sensors live and recordable — the basis for later process monitoring.
• The alarm report states plainly that this machine delivers no controller alarms, and that limit alarms can be defined instead.

The oldest, least connected machine in a hall can stand in the same overview as the newest — with labels that keep the comparison fair. The same approach works for any older machine: sensors, an EdgeBox, one calibration.