Linear encoders... Noob question

[Robertspark]

Linear encoders (glass scale )

Do they retain or provide absolute position without the need for homing?

Or would I still need to home the machine at pc boot / reboot

Thanks

[Vmax549]

It depends on what type you have INC or ABS. ABS hold their info by a battery backup and know where they are at any given point in time. The motion controller would have to be able to TALK to an abs encoder to be able to interface.

In a nutshell, (;-) TP

[beefy]

The glass scales on my lathe and milling machine also have a "hard" reference point (basically their way of being homed after power loss, etc).

So just like knowing your work offsets from your typical home switches, if you know the glass scale offsets from their "hard" reference points, you can always get back to where you were, even if any glass scale backup battery died during machine power off.

Keith.

[Robertspark]

Thanks Terry and Keith,

I was thinking of wiring some ahem... Chinese.... Glass encoders up that are normally used with dro kits in the UK.

I suspect they will just be incremental, the absolute bit will be in the dro control box.

I'll give them a miss then and get some sort of a static homing reference point