The system may also include {HEAD ~ an infrared transmitter} for transmitting {TAIL ~ infrared command signals} to a keypad controller having an internal infrared receiver or to an external infrared receiver adjacent one of the drive units 
for transmitting
The system may also include { HEAD ~ an infrared transmitter } for transmitting { TAIL ~ infrared command signals } to a keypad controller having an internal infrared receiver or to an external infrared receiver adjacent one of the drive units
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH