Switching On or Off the Instrument
R&S
®
ETL
41Getting Started 2118.4130.02 ─ 04
7 Switching On or Off the Instrument
Shock hazard
Observe the basic safety instructions delivered with the R&S ETL, especially the
instructions on electrical safety.
Be aware that in standby, the R&S ETL is still power-supplied.
For an overview on available power supplies, refer to Chapter 6.2, "Connecting to the
Power Supply", on page 38.
7.1 Instrument States
Three different instrument states exist:
On (ready)
The R&S ETL is supplied with power by one of the available power supplies (see also
Chapter 6.2, "Connecting to the Power Supply", on page 38). After booting, the
R&S ETL is ready for operation. A green LED above the [ON/STANDBY] key indicates
this state.
Standby
Only available if the R&S ETL is connected to the AC power supply (AC power switch
in position I; for details, refer to Chapter 5, "Interfaces and Connectors", on page 17). A
yellow LED above the [ON/STANDBY] key indicates this state. Parts of the R&S ETL
are still active, e.g. the oven of the OCXO unit (OCXO Reference Frequency option,
R&S FSL-B4) is kept active. To prevent the R&S ETL from overheating, the fan
remains active.
If switched on in this state, the R&S ETL will rapidly resume operation. It preserves the
current settings and when switched back on, the last measurement is displayed.
Off
The R&S ETL is switched off completely. Both LEDs are off. When switched on again,
the R&S ETL starts booting. If the OCXO unit (OCXO Reference Frequency option,
R&S FSL-B4) is used, an extended warm-up phase as specified in the data sheet is
required.
Instrument States