Help with Pace ST 50 soldering station (SOLVED)

[pro-sl]

I recently acquired a Pace ST 50 station with TD-100 soldering iron. It is in great shape but going by the design and the 1.2 software version it looks like an earlier production. I went through all the settings in the menu and it appears as if one feature is missing. If one is in the setup menu they can choose C or F, temperature range limits, set back time, auto shut off and THC calibration offset.
My menu ends after auto shut off time. I am not sure if THC calibration offset is missing or if it only is available with special tips or irons.
From reading in the manual about the three different offset modes I am not quite sure what the offset actually is or refers to but my guess is that it has something to do with calibration.
When changing a tip with the unit on I get an amber light and the display reads O(or zero)SE then a green when the tip is inserted again. Then it displays the rising temperature and acts normal. This behavior is not mentioned in the manual and I am wondering if it is something that is unique to older/earlier models.
I am also trying to figure out if the unit is operating properly. I only soldered something for 5 seconds and it seems fine in that regard.
Thanks for any input.

Update: I emailed Pace directly and they got back to me right away. My station is indeed an earlier production year and the older software version does not include the offset mode functionality of the newer stations. Other than that they are the same.