[ecnels]

We have a Romi D760 VMC. Recently, the spindle encoder went out causing a position coder disconnect error on the spindle amplifier. After troubleshooting, we ordered a new encoder from Heidenhaim using the part# in the Maintenance Manual for this machine. This newer version (ERN420) of the old encoder from Heidenhaim delivers 2048 PPR. The position coder disconnect error is gone; however, the speed shown on the Fanuc Operator Panel is about twice the actual spindle speed. Example: Operator enters an "S500 M03;" and the spindle actually turns at 500 RPM (hmmm, expecting the Spindle Screen (enclosed picture) to show 500, not 533RPM, since Gcode is "S500'); nevertheless, a photo-tachometer shows the spindle at 500 RPM and the Operator Panel shows the Spindle Speed at 1,000 RPM. Also M19 Spindle Orientation doesn't work (spindle keeps rotating at a couple of hundred rpm).

Fanuc said to check Parameter 3706 [Position Coder Gear Ratio]. It's set at "x1", i.e. 00 and if we change it to x2, x4 or x8, the Speed showing on the Operator Panel simply continues to double from it's already-doubled showing. This is telling us that no matter what the Heidenhaim Encoder Model# shows in the manual (evidently this 2048 PPR model), the required spindle pulse coder should actually be 1,024 PPM, so the question: Is there a way to adjust parameters and make this higher resolution, incremental pulse coder work with this Fanuc 21i system or do we have to order a 1,024 version?

Thanks!

Ev

[pippin88]

Can you set the gear ratio to 0.5?