Replacing elderly Anilam 1100 control system on vertical mill

[Neale]

My understanding is that the G28 reference position is not necessarily the home position although I agree reading the manual that for the 1000MDb, they might be the same thing. For example, in both Mach3 and the MyCNC software that I'm currently using with my router, you can separately define the G28 position (machine coordinates, obviously) and in fact I set it over the fixed touchplate set into the bed of my machine. Definitely not the home position! But, control systems vary so maybe SZGH and the clones think differently. I have found where the home position and homing parameters are set, use of index pulse, offset of machine zero from physical home position, etc, and I had hoped that G28 was defined in the same parameter set. But I don't think it's quite that easy...

It does make sense to me that there are separate sets of coordinates for machine home and tool change position, but maybe that's just thinking that's been conditioned by what I have been using to date. Again, in my case, it's useful to have these separate as my G28 position is over the bed while the physical home position is over the floor - less useful when you drop a tool during a tool change!

Actually, thinking about homing, I do need to check if the index pulse gets sent back to the controller. I'm not sure that the encoder pulse outputs (which are available on the motor) are cabled through to the controller. I don't think that we have a cable from SZGH that connects to the encoder pulse input socket on the back of the controller - I'll need to double-check that. It would mean that the controller display would act as a DRO if the manual handwheels were used. Although, as discussed elsewhere, I would discourage the owner of the machine from doing that!