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Channel Bonding Temperature Compensation Using SCPI

Temperature compensation applies to M9384B VXG.

After performing a bonding process, subsequent temperature changes affect the phase relationship between channel 1 and channel 2 at the carrier frequency. This sensitivity to temperature is mitigated by a temperature compensation algorithm which adjusts the phase relationship between the two channels to better maintain the phase relationship between the two channels at the carrier frequency. If the periodic adjustment of the phase relationship disrupts the measurement process, then periodic temperature compensation can be disabled. Instead, temperature compensation can be performed on demand when appropriate.

The instrument, when Bonding has successfully completed, will utilize temperature compensation. This process gradually adjusts the phase between the two channels as the ambient temperature changes. The amount of time between compensation, and the sensitivity to the magnitude of the temperature fluctuations can be adjusted.

Enable Periodic Temperature Compensation

Temperature Compensation Cycle Time

Temperature Compensation Averaging

Immediate Temperature Compensation

Temperature Compensation Coefficient

Measured Bonded Temperature

Measured Periodic Temperature

Immediate Measured Temperature

Enable Periodic Temperature Compensation

Enable or disable temperature compensation. If enabled, the instrument will periodically adjust the phase of the channels to compensate for temperature drift (this applies to Bonded Groups after a successful bonded calibration, or a BND file has been loaded).

Temperature Compensation Cycle Time

Specify, in seconds, how often temperature compensation is performed (which affects the phase relationship between the channels during waveform playback). The number of cycles required to completely adjust for a temperature change is dependent on the temperature compensation averaging.

The amount of time to fully compensate for a single temperature change is approximately the cycle time * averaging. For the defaults, it will take approximately 100 Seconds to fully compensate for a single temperate change event. When temperature compensation is used, the sensitivity of the phase (between channels) to temperature in Degrees Celsius is approximately 3 Degrees in phase per 1 Degree Celsius. The responsiveness of periodic temperature compensation to changes in ambient temperature tuned to the environment by adjusting these values. Decreasing the cycle time, results in more frequent phase adjustments. Decreasing the averaging results in potentially greater changes to phase each cycle.

Temperature Compensation Averaging

Adjusts, approximately, how many compensation cycles are required to completely adjust the phase to mitigate a single change in temperature. A value of 0 fully adjusts phase for the currently measured temperature change each cycle; a setting of 10 requires approximately 10 cycles to fully compensate the phase for a single change in temperature.

The amount of time to fully compensate for a single temperature change is approximately the cycle time * averaging. For the defaults, it will take approximately 100 Seconds to fully compensate for a single temperate change event. When temperature compensation is used, the sensitivity of the phase (between channels) to temperature in Degrees Celsius is approximately 3 Degrees in phase per 1 Degree Celsius. The responsiveness of periodic temperature compensation to changes in ambient temperature tuned to the environment by adjusting these values. Decreasing the cycle time, results in more frequent phase adjustments. Decreasing the averaging results in potentially greater changes to phase each cycle.

Immediate Temperature Compensation

At any time after the bonding process has been successfully completed (or a BND file has been loaded), an immediate temperature compensation cycle can be triggered. This will adjust phase between the channels to fully compensate for temperature change since bonding was performed. Immediate temperature compensation can be performed regardless of periodic temperature compensation being enabled. Immediate temperature compensation allows control over when the phase is adjusted (and momentary changes to the generated signal).

Temperature Compensation Coefficient

The nominal temperature compensation coefficient, 30.0 Degrees Phase / Degree C, will yield a phase drift of approximately 3.0 Degrees of Phase per 1.0 Degree C change in temperature. The phase drift appears as a discrepancy in the phase between the two channels at the carrier frequency. However, the phase sensitivity to temperature can vary between instruments. Experimenting with this value may result in further reduction in the phase drift due to temperature (increasing the value will increase the phase adjustment, while reducing the value will reduce it).

This setting is available to adjust the temperature compensation to temperature changes.

Measured Bonded Temperature

Query only command that returns the measured temperature at the time the bonded calibration was performed in Degrees Celsius.

Measured Periodic Temperature

Query only command that returns the most recently measured temperature for periodic temperature compensation in Degrees Celsius.

Immediate Measured Temperature

Query only command that returns the measured temperature at the time of immediate temperature compensation in Degrees Celsius.