Mitsubishi Z51 alarm: Reference position not established

Mitsubishi/MELDAS indicates that the absolute axis position/reference system is not established. It is an alarm from the Sobrecarrera area, and in the catalog it is listed as “Reference position not established”. On the machine you notice it like this: Axis with no reference, It doesn't let you enter automatic, Appears after absolute battery or hit.

On the shop floor it almost always comes from one of these causes: Absolute system not initialised, Absolute battery dead, Loss after encoder alarm, Cambio de hardware. Rule out the most likely one on your machine first, before touching parameters or swapping anything.

Reset after establishing the reference by the proper procedure. Resetting without fixing the cause first only hides the problem: Mitsubishi Z51 trips again and, in the meantime, you keep working with the machine in bad shape.

With the machine stopped and in a safe state, start with these checks: Note the affected axis, Do not machine without a reference, Seguir procedimiento de absolute position setup. That alone will tell you whether it is the program or whether you need to raise a maintenance job.

With Mitsubishi Z51 active, avoid this: Do not skip the absolute position sequence, Do not move automatically without reference. Skipping any of these points is what turns a minor stop into an expensive breakdown.

If you require absolute calibration or adjust parameters. If you are not sure how far it goes, stop the machine and report it: a repeat alarm always works out cheaper than a crash.

It is a stop alarm: the cycle will not continue until you fix the cause. It does not always mean serious damage, but it leaves the machine where it is and you have to check it before running again. Guidance reference. Always confirm the full text in the exact machine/control manual.