I have not worked in apps 9 but it was there in apps 8 and is there in apps10. 

you need to setup testpoint / parameter for the equipment, the create a pm action which has start value, interval etc defined and then proceed to setup the criteria/condition tab on pm with the hours interval / start value. 
 

Yes it is possible in App 9 version.

In the same PM action:

To specify the time interval – Use General tab. Start value, unit, interval, interval unit needs to be entered under Maintenance plan (set Generatable = yes).

To specify every so many hours – Use Condition tab. Enter the test point, parameter, and other details based on your parameter type (if accumulated – start value, interval: if limit – min value, max value)

Thanks for the reply - I have the PM set up as described.  Maybe this is happening the way it is suppose to - I was thinking that if the condition generated the pm and the work order was completed the calendar based pm would be generated on the date the work was done.  Also if the work was done on the calendar how does the condition get a new value to base its generation value?

Again i cannot speak for apps 9, but during our apps 10 implementation (still ongoing) we did report it as a bug that we observed that If it was the condition pm line that was generated and reported it would update the condition lines on pm action but also the calendar based lines in maintenance plan whereas if it was the calendar line that generated and reported only the next calendar lines would be updated but not the condition ones. 
 

this has been fixed now in apps 10. 
 

But based on the date reported the system will calculate the condition value. 
this “feature” likewise had updates made to it in apps10 because it had a really strange behaviour. 
 

I wonder if the case is the same in apps 9