Automation Direct ProSense DPM2 Series User Manual page 25

Configuration Lock-Out Continued
It is posible to configure SHIFT key lock-out for MAX/MIN function in the same
  
way as previous configurations.
  
When lock-out is enabled (selecting "YES") it is not possible to visualize maximum
or minimum values by pressing SHIFT key, although instrument internally
continues detecting and saving new extreme values reached by input signal.
Once the instrument programming is completed, if there are parameters that are going to be
frequently changed, a partial lock-out is recommended. A total lock-out is recommended when
configuration parameters will be constant for a long time.
Changing default security code and keep new one in a safe place is also strongly recommended.
User Manual - DPM2 Series Process Panel Meters
DPM2 Process User Manual, 1st Edition
25