Are some DRO's Write protected?

Here is a section of my macropump:

sov=GetoemDRO (202)

If  (sov <= 9500) Then
   'set spindle speed to 9000 RPM
   ActivateSignal (output6)
   DeActivateSignal (output7)
   DeActivateSignal (output8)
   DeActivateSignal (output9)
   SetOEMDRO (39,9000)
   End If
   
If (sov > 9500) And (sov <= 10500) Then
   'set spindle speed to 10000 RPM
   DeActivateSignal (output6)
   ActivateSignal (output7)
   DeActivateSignal (output8)
   DeActivateSignal (output9)
   SetOEMDRO (39,10000)
   End If

Everthing is working fine except the SetOemDro command.  Any ideas?
Thanks
Eugene

Well, I must have looked over the wiki 5 times and didn't see the "not all dro's can be written" statement.  Sometimes I have to post a ? here in order to be able to see!

You might try DRO 817. Its called "Spindle Requested DRO".

39 is called True Spindle and it shows the measured speed, so you cant change that.

When Im writing wizards I often open the 1024.set screen and select buttons I want to use and see their properties. Its often quicker than trying to read through the long lists of codes.

You might also use a Code command and issue the gcode for speed- Code "s 9000" or whatever speed you want. I think its legal to use an S word alone