22 will determine what speed setting the motor controller 24 should use and transmit such speed setting to motor controller 24 once a particular speed setting is received motor controller 24 will automatically regulate the motor 20 a or 20 b to maintain the speed corresponding to the speed setting it has received from main controller 22 when main controller 22 first receives the part number information identifying whether a five inch cutting unit 4 or a seven inch cutting unit 4 is attached main controller first waits until all of the expected plurality of cutting units 4 have reported in for example if mower 2 is expected to have five reel cutting units 4 installed all five reel cutting units 4 must be online to main controller 22 as shown at block 38 when all the expected reel cutting units 4 have come online to main controller the process branches to block 40 which determines whether the part numbers identifying the reel cutting units 4 are all the same to signify that all of the attached reel cutting units 4 are the same size i e all cutting units 4 are either five inch cutting units or seven inch cutting units if a mismatch is detected at block 40 meaning one or more of the cutting units have a different size than the other cutting units main controller 22 at block 42 displays a fault to the operator on the information center and prohibits or prevents operation of any of reel cutting units 4 until the mismatch issue is resolved if block 40 determines that all of the reel cutting units 4 are the same size main controller 22 at block 44 correlates the part number for such motors 20 a or.