Keysight 34942A Comms Errors

[GavinSheehan]

Has anyone used a Keysight 34942A with LabVIEW before? I have the multiplexer in bank one and trying to configure the frequency measurement of channel 1101 but I'm getting the error "Channel not able to perform requested operation". It is error code 308. No explanation in the service guide as to how to resolve this error code. My code is communicating with the DMM correctly and the DMM is showing the RF Channel 1101 as closed but I'm not able to interact with it. The  I'm using the default "AG34980 Configure Frequency and Period" instrument driver. This is my first time using an RF mux with this DMM. Any help would be appreciated. Thanks.

[GerdW]

Hi,

this seems to be a Keysight problem - why don't you ask them?

[ben64]

When you close channel 1101 the mainframe connect it to the common output of bank 1, not to the internal DMM and there is no way to map it directly to the DMM. That's why you get the error. What mainframe are you using, 34980? If so it can't be used to measure RF frequencies.

Ben64

[GavinSheehan]

Thanks for the reply. Yes, I'm using a 34980a with the multiplexer installed at the rear. Is there any sort of workaround you'd know of to measure RF frequencies with this combination?

[GavinSheehan]

I have reached out to Keysight also and awaiting a response. I wasn't sure if it was a hardware or software problem I was having so said I'd ask the question here also.

[ben64]

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@GavinSheehan wrote:

Thanks for the reply. Yes, I'm using a 34980a with the multiplexer installed at the rear. Is there any sort of workaround you'd know of to measure RF frequencies with this combination?

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No, this equipment is not made to measure RF Frequencies. You need to connect the common output of the 34942A to a  Frequency Counter (and use a matching pad to convert the 75Ω impedance to 50Ω because the freq counter inputs are all 50Ω or 1MΩ) or to a spectrum analyzer.

Ben64

[GavinSheehan]

Are you sure? How can they sell it stating that it is for the 34980A when it actually isn't?

http://www.keysight.com/en/pd-434724-pn-34942A/quad-1x4-75-ohm-15-ghz-multiplexer-module-for-34980a?...

[ben64]

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GavinSheehan a écrit :

Are you sure? How can they sell it stating that it is for the 34980A when it actually isn't?

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Yes it is for the 34980A and the module does what it is meant to do: multiplex RF signals to the module common output. It is not meant to measure RF signals with the 34980A. A common application would be to connect the output of an RF device to the common output of bank 1 of the 34942A and connect RF measurement equipments like power meter, spectrum analyzer, frequency counter and high speed scope to channels 101 to 104. The 34980A is used to switch the device output to the various equipments.

In the link you posted the module description says:

The Keysight 34942A RF multiplexer module for the 34980A Multifunction Switch/Measure Unit offers bi-directional switching broadband signals. High channel isolation ensures quality dynamic range measurements with your oscilloscope, spectrum analyzer, or other instrumentation.

Ben64