If the rack number is 2 (or higher) /0, you will need to Abort Boot to clear the rack number. The CEM+ processor will then hold the configuration that you give it. To Abort Boot, hold the double back ...If the rack number is 2 (or higher) /0, you will need to Abort Boot to clear the rack number. The CEM+ processor will then hold the configuration that you give it. To Abort Boot, hold the double back arrow (<<) while resetting or powering the rack on until you see “Abort Boot” on the screen. If your processor shows a rack number of 1/0 and still will not hold a configuration, or Abort Boot does not help, please contact ETC Technical Services.