Agilent Technologies N8201A manual Ieee 1588 LED clock status has the following states

4Front and Rear Panel Features

1588 LED

The IEEE 1588 LED clock status has the following states:

State of the Clock	Clock Status	Illumination
OFF	Not synchronized	None
ON	Synchronized, clock is IEEE 1588 Slave	Solid green
ON	Synchronized, clock is IEEE 1588 Master	Blinking green (once
		every second)
ON	Synchronized, clock is IEEE 1588 to	Blinking green (once
	Grand Master	every two seconds
OFF	IEEE 1588 is in a fault state	Solid red

COHERENT CARRIERS

N O T E	Do not remove the cables connecting the coherent carrier inputs and outputs. These cables
	are connected at the factory and must remain so for proper instrument operation.

3-7 GHz 1st LO In Provides the 1st LO input signal (3 to 7 GHz) to the downconverters internal LO distribution circuitry.

3-7 GHz 1st LO Out Provides the 1st LO output signal (3-7 GHz at +15 dBm max) as a

coherent carrier reference for phase locking two receivers.

3.6GHz 2nd LO In Provides the 2st LO input signal (3.6 GHz) to the downconverters internal LO distribution circuitry.

3.6GHz 2nd LO Out Provides the 2nd LO output signal (3.6 GHz at +3 dBm) as a coherent carrier reference for phase locking two receivers.

84 Agilent N8201A Performance Downconverter Synthetic Instrument Module, 3 Hz to 26.5 GHz