What does this mean? "CO 0.84" This shows up when I pressed (ramp+down arrow) at same time. The numbers changed too quick for me to see the original setting, but now it is at 0.84. Cannot find clinician directions. User manual does not help.

Thank you so much for the previous help, but I seemed to have changed nsomething I didn't mean to when trying to adjust the pressure. I held down the Ramp button and the Down-Arrow button and numbers started changing, from what I dont know because they changed so fast. In some kind of program mode I...

Thank you. I read this post a few days ago, but for the past few days it did not respond as indicated. Tried again just now and it actually worked, wow.

Please, after days on browsing the internet and reading everyone's instructions on how to change the air pressure, no explains mine. Please, how do I change the air pressure setting on a Resmed Tango C Series??