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What is the max sample clock using the Shielded Single-Ended Flying-Lead Cable



What are the max practical limits for the sample clock using the Shielded Single-Ended Flying-Lead Cable?


I am playing with the Labview embedded example "Dynamic Generation and Acquisition Source" using the Shielded Single-Ended Flying-Lead Cable and the PXIe-6556.

This example write in the channels 0-7 and read in the channels 7-15.

It also export the sample clock and data active event so we have a "Source Synchronous"


I change the original example to set the input impedance to 50ohm and VH and VL voltatages.Write 3.3V - 0V and read 0.5V 0.3V.


The problem is the signal integrity at higher frequencies. Please see the picture attached.


Sample clock 30MHz










Error: PLL could not phase-lock to the external reference clock.

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Hello engfpe,


According Hardware manual the Maximum Sample Clock rate is 200 MHz.


Is not clear for me if your error message was received on LabVIEW or on your Agilent Scope, and I don´t know your Agilent Scopes specifications. Neither I don´t know what exactly you are trying to generate, maybe if yo ucan clarify more your application and your issue I can help you more.


Best regards,

Abel Souza
Engenheiro Eletrônico
LabVIEW User since 8.5
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The error message came from the Labview. The scope is a Agilent MSO9254A Oscilloscope 2.5 GHz.

I am using the example  "Dynamic Generation and Acquisition Source" to verify which is the max frequency  I can send the digital signals in the source synchronous configuration.


There is any circuit I just connect input and outputs directly. In the scope we can see that the "ddc clock out" signal" is degrading when I increase the frequency.

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