Orion's will only go down to 50% of rated maximum power.
IE: 110 watt radio will only go down to 55 watts.
M7100 high-power units are the same, only 50% normally.
M7100 mid/medium-power units can go lower. Usually down to eight(8) watts.
( ...I run my M7100's at 8 watts for short range car-to-car comms)
When in doubt, look at the tracking data for your radio.
On the System Tab in the personality file, under power level, leaving it at MAX runs the radio at full rated output power. Something less than max runs the radio at that power level designated by the numeric value entered, but only IF THE RADIO IS CALIBRATED FOR THAT POWER LEVEL.
IE:
If the radio is calibrated to handle power levels from 40 to 20 watts, entering MAX or 40 will give you 40 watts.
Entering in 50 will NOT give you fifty watts.
Entering in 36 watts will give you thirty-six watts.
Entering in 20 will give you twenty watts.
Entering in 5 will NOT give you five watts, but instead 20 watts.
I hope this helps.