Ku-band receiver commands and information.

Index

The Ku-band receiver is a single band, single polarization dicke-switched receiver. This page provides information about how to control and monitor this receiver.

Ku-band receiver commands

Commands that are specific to the Ku-band receiver, are sent as text command strings using the tell command. Beware that the contents of these strings are not checked by the script parser when scheduling scripts are parsed, but rather by the receiver controller when they are actually sent to it.

Setting configuration values

Receiver configuration values are sent to the receiver using the set command. For example, the following command turns on the HEMT, turns off the antenna-beam calibration signal, and sets an attenuation of 4dB.

  tell kuband, "set hemt=on, ant_cal=off, atten=4"

Note that this command set 3 different parameters. Other parameters that are not changed by a given set command, are left unchanged. The following is a list of the parameter that can be assigned, along with the values that can be assigned to them, via the set command:

hemt

Set the state of the first-stage HEMT of the receiver, as follows:

hemt=on: Turn on the HEMT.
hemt=off: Turn off the HEMT.

dicke_mode

Set the operating mode of the dicke-switch, as follows:

dicke_mode=ant: The switch is left indefinitely in the antenna-beam position.
dicke_mode=ref: The switch is left indefinitely in the reference-beam position.
dicke_mode=switched: The dicke-switch alternates between the antenna and reference beams, changing state every dicke_period milliseconds.

dicke_period

Set the periodic interval at which the dicke-switch alternates between the antenna and reference beams. This is only used when the dicke_mode parameter is set to switched. The interval can be any of the following, which are integer multiples of the 1ms sampling time of the receiver.

dicke_period=1: Change the state of the switch for every 1ms sample.
dicke_period=2: Change the state of the switch every 2nd 1ms sample.
dicke_period=4: Change the state of the switch every 4th 1ms sample.

Note that the above values were chosen to be produce an integral number of switching cycles per second.

ant_cal

Set the on/off state of the antenna-beam calibration signal, as follows:

ant_cal=on: Turn on the antenna-beam calibration signal.
ant_cal=off: Turn off the antenna-beam calibration signal.

ref_cal

Set the on/off state of the reference-beam calibration signal, as follows:

ref_cal=on: Turn on the reference-beam calibration signal.
ref_cal=off: Turn off the reference-beam calibration signal.

ant_noise

Set the on/off state of the antenna-beam noise signal, as follows:

ant_noise=on: Turn on the antenna-beam noise signal.
ant_noise=off: Turn off the antenna-beam noise signal.

ref_noise

Set the on/off state of the reference-beam noise signal, as follows:

ref_noise=on: Turn on the reference-beam noise signal.
ref_noise=off: Turn off the reference-beam noise signal.

atten

Specify the attenuation to add in the signal path, as follows:

atten=n: Set the attenuation to n dB, where n must be an integer from 0 to 11.
atten=inf: Open a switch in the signal path, to set the attenuation to infinity.

time_nfit

Specify the number of recent seconds whose raw 1ms timestamps are to be used to fit for the timestamps of the current second, in place of using the raw measured timestamps.

time_nfit=n: Set the number of seconds to n. At the end of each second, a line will be fitted through the raw measured timestamps of this second and the raw timestamps of the previous n-1 seconds, fitted versus the ordinal sample number. The recorded timestamps of the second will be taken from this line at the ordinal sample number of each sample in the second.
time_nfit=0: Don't fit for corrected timestamps. Just record the raw timestamps.

Martin Shepherd (5-May-2010)