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TPS2372-4EVM-006: How to test 802.3bt PoE PSE?

MARMONIER Cedric
Prodigy 20 points
Part Number: TPS2372-4EVM-006

Tool/software:

Hello,

I'm building a 802.3bt PoE PSE and I want to test it.

I see there is the eval board TPS2372-4EVM-006. It is possible to test my PSE with it?

I want to test:

- single and dual-signature.

- power limitation in using device classification.

- power demotion.

- autoclass.

Can I test my PSE board with TPS2372-4EVM-006?

How to test dual-signaure? ...I don't see a dual-signature mode in the eval board.

How to test autoclass? ... How can I do to configure the maximum power for the PD?

How to test power demotion?... how the PD know which class is selected by PSE?

  • 0
    TI__Mastermind 37061 points

    Hi MARMONIER,

    How to test dual-signaure? ...I don't see a dual-signature mode in the eval board.

    - You will need two TPS2372-4EVM-006 and one board to split the 4 pairs wire to 2 x 2 pairs.

    How to test autoclass? ... How can I do to configure the maximum power for the PD?

    - Connect J5 

    How to test power demotion?... how the PD know which class is selected by PSE?

    - Please refer the table below. For example you can set PSE to Type-2 power limit. Then use TPS2372-4 to select Class-5, -6, -7, -8 at pin J9. 

    PSE Allocated Power

    PD(30W)

    Requested

    Class-4

    PD(45W)

    Requested

    Class-5

    PD(60W)

    Requested

    Class-6

    PD(75W)

    Requested

    Class-7

    PD(90W)

    Requested

    Class-8

    Type1

    15W

    Power up at 15W

    Power up at 15W

    Power up at 15W

    Power up at 15W

    Power up at 15W

    Type2

    30W

    Power up at 30W

    Power up at 30W

    Power up at 30W

    Power up at 30W

    -

    45W

    Power up at 45W

    Power up at 30W

    Power up at 30W

    Power up at 30W

    Type3

    60W

    Power up at 60W

    Power up at 60W

    Power up at 60W

    -

    75W

    Power up at 75W

    Power up at 60W

    Best regards,

    Diang

  • 0 in reply to Diang Xing
    Prodigy 20 points
    I thank you.
    In the event of a power demotion, how does the PD indicate to the PSE that it is prepared to accept it? Is it mandatory for the PD to accept power demotion? Is there a acknowlegment system between the PSE and the DP?

    Can PSE know if it is connected to a dual-signature device if only 2 pairs?.. For example, what happens if I separate the cable but only connect one TPS2372-4? Will the PSE think that the remote TPS2372-4 is in single-siganture?

    How should PSE process in dual-signature mode when it needs to activate power demotion? How should it choose which pairs to demotion? Is there a fixed rule to define the priority pair?

  • 0 in reply to Diang Xing
    Prodigy 20 points

    When I see this table, I'm not sure that connecting two TPS2372-4 is enough to simulate a PD dual-signature. Single and Dual signatures do not appear to be the same for a given class :

    Source : https://ethernetalliance.org/wp-content/uploads/2019/08/EA_PoE_dspd_Rev2e_090419.pdf

  • 0 in reply to MARMONIER Cedric
    TI__Mastermind 37061 points

    Hi Marmonier,

    The PoE team will be traveling until Feb 4th. Sorry for the delay on the response and thanks for your patience.

    Best regards,

    Diang

  • 0 in reply to Diang Xing
    TI__Mastermind 37061 points

    Hi Marmonier,

    Thanks for your patience.

    It is kindly of "mandatary" for the PD to accept power demotion. PD as a power receiver is relative passive compared to PSE as power deliver. While PD's TPH/TPL/BT will show the real classification after power demotion.

    For example, if PD set Class-8 and PSE can give Class-8, then TPH/TPL/BT = L/L/L. But if PSE only give Class-6 due to power demotion, then TPH/TPL/BT = L/H/L

    Best regards,

    Diang

  • 0 in reply to Diang Xing
    TI__Mastermind 37061 points

    For dual-signature, classification will be proceeded on two PDs individually. And each PD will know what is the "real" class is given by number of class events and pulse width. And each PD's indicator, like TPH/TPL/BT, will display the "real" given class individually. 

    Best regards,

    Diang

  • 0 in reply to Diang Xing
    Prodigy 20 points

    I thank you,

    The class 5 is the same between dual-signature and single-signature ?... if it is the same, how PSE know if there is a single or dual signature if the second PD isn't connected ?... it is important because class 5 power in single-signature mode it isn't the same that dual-signature mode.

  • +1 in reply to MARMONIER Cedric
    TI__Mastermind 37061 points

    Hi Marmonier,

    Yes, both single and dual signature class-5 will have 4 classification events. The PSE can do connection check and parallel detection at Alt-A and Alt-B to tell the PD side is configured as single and dual. Single signature PD will have 1/2 Rdet measured in parallel check but dual signature PD will have Rdet. 

    Besides, if you want to do dual-signature tests, you will need two TPS2372-4EVM-006 boards and each set as Class-5. Also you will need a CAT5 split board to split the 4-paris from PSE to 2-pairs Alt-A and Alt-B to the 2 x TPS2372-4EVM-006 respectively.  

    Best regards,

    Diang

  • 0 in reply to Diang Xing
    Prodigy 20 points

    OK, I thank you.