Arthur, not stuck my nose in before as I can't help out because many of these commercial controllers are special to the manufacturer and / or machine.
Silly things like hold the prgm key in until it boots then release.

Because it's a commercial control you could ask on the CNC machining page on Practical Machinist, there are some knowledgeable people there and few UK posters who may have had M250 experience.

http://www.practicalmachinist.com/vb...hining-21.html

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