This PDF is the connector/cable wiring diagram for current models of GUV radiometers. For GUV-511s with cables made prior to 2002, pins 4, 5, and 7 were not used, so they may not be connected on your cable.
 
			This PDF is the connector/cable wiring diagram for current models of GUV radiometers. For GUV-511s with cables made prior to 2002, pins 4, 5, and 7 were not used, so they may not be connected on your cable.