:CHANnel:WAVelength
Command Syntax
:CHANnel{1:8}{A|B|C|D}:WAVelength {USER | WAVelength{1:3} | NAPPlicable}
Where the required specifier {1:8}{A|B|C|D} identifies a channel by its module slot number and channel letter. For example, channel 3C (CHANnel3C).
The channel specifier will fail if it does not include a slot number. If instead the suffix's channel letter is missing, the command defaults to letter A. As a result, the best practice is to always explicitly specify the channel by including both the module slot number and channel letter.
Query Syntax
:CHANnel{1:8}{A|B|C|D}:WAVelength?
Query Response
{USER | WAV1 | WAV2 | WAV3 | NAPP}
Description
On optical channels, selects the calibrated wavelength for measurements. Modules can support up to three factory-defined wavelengths. The command argument identifies a wavelength that is shown in the Wavelength field of the Wavelength field of the Channel Setup dialog. For example, WAVelength2 identifies the second setting from the top in the listing, 1310 nm, as shown in this picture. The module will have one factory calibration for each factory-defined wavelength. The USER argument is only valid if this user-defined calibration has been performed.
Optical channels use an internal photo detector to receive an optical signal and then convert this signal to an electrical signal. The FlexDCA then uses a conversion gain (factor) to accurately display the signal in optical power units. For example, 1 mW of optical power yields a 28 mV electrical signal. Optical channels are factory calibrated at a specific wavelength to provide both accurate display of the received optical waveform in optical power units and measurement of the signal's average power. Refer to Optical Calibration to learn the calibrated wavelengths of individual modules.
Recommended Alternative
The :CHANnel:WAVelength:VALue command is the preferred method of setting the channel wavelength as it sets the value explicitly rather than implicitly thereby making your code more reliable and easier to read. Use the :CHANnel:WAVelength:VALue:VSET? query to return a list of all supported wavelengths.
Simulated optical modules do not support wavelength selection and do not support this command. Sending this query to a simulated optical modules returns NAPPlicable.
The Wavelength selection is only displayed for plug-in modules with internal optical channels.
Prior to configuring the channel to use a user-defined wavelength, you must first perform an optical calibration on the wavelength.
Example Command Sequence
The following commands selects the second wavelength shown in the Channel Setup dialog, which in this example is 1310 nm.
:CHANnel2A:WAVelength WAVelength2
or
:CHANnel2A:WAVelength:VALue 1.31E-6