Originally Posted by
cncsnw
Actually, your PLC program uses "high mid" range instead of "low mid" range, so the ratio associated with M42 (and formerly with Aux2) would be in Parameter 67, not Parameter 66.
Also, you will need to modify the M41, M42 and M43 macros slightly if you still want to be able to use the Aux keys to select range even after using one or more of the M functions.
Yes, you would typically pick three or four ranges you want to use, and set those up in Parameter 65-67. There is no need to shift among 12 or more different gear ranges when you have a variable-frequency spindle drive.
Hard-wired range-detect inputs are not required, but they are convenient because you don't have to remember to push an Aux key or run an M function to match each time you shift the gear lever.
If you want to use four ranges instead of three, then you would need a couple minor modifications to your PLC program, around lines 1790-1800. That section, which sets and then uses SpindleRange_W values from 1 through 4, has standard 4-range support.
If you wanted to use more than four ranges, then you would need to define your own set of ratio parameters, separate from or in addition to P65 - P67 (e.g. using parameters in the 900-series), and define what M functions or Aux keys you wanted to select those ranges. But that really shouldn't be necessary.
Finally, the values in P65 - P67 are not the ratio of lower-range spindle speeds to the spindle motor; they are the ratio of the lower-range spindle speeds to the high-range speed. We generally don't know or care exactly how fast the motor is turning. Threading will work fine in any and every range, as long as your spindle encoder is belted 1:1 to the back of the spindle (and not mounted on the motor).