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Original question:

[FAQ] DP83TD510E: DP83TD510E : Announcing the availability of IEEE 802.3cg 10Base-T1L Ethernet PHY for evaluation

DP83TD510E: Clarification on attainable distance

Mike Strauser
Intellectual 370 points
Part Number: DP83TD510E
Other Parts Discussed in Thread: PROFIBUS

I am confused by the datasheet for this part.  It states 1700+ meters for both 1V and 2.4V.  That can't be right.

Also, under what conditions can you expect this kind of distance?  Will any Type A Fieldbus Cable achieve this or do you have to use something special?  If so what is it?

Mike.

  • 0
    TI__Genius 11725 points

    Hi Mike,

    This distance has been characterized using a forced speed link with the 6XV1830-5EH10 cable, which is compliant with the  IEEE 802.cg cable spec. Results may vary using other cables or using auto-negotiation rather than forced mode. Please let me know if you have any other questions.

    Thank you,

    Nikhil

  • 0 in reply to Nikhil Menon
    Intellectual 370 points

    You didn't answer my first question.  So here is my list:

    1. Why is the maximum distance shown in the datasheet as 1700m for both 1V and 2.4V?

    2. Do you have test results with other kinds of cables - such as Type A Fieldbus cable?  If so can you share what you found?

    Mike.

  • 0 in reply to Mike Strauser
    TI__Genius 11725 points

    Hi Mike,

    To answer your questions:

    1. The DP83TD510E has two output differential voltage p2p modes, 2.4V p2p and 1V p2p. I should clarify that this distance of 1700m has been characterized for both p2p modes. As mentioned, this distance has been characterized using a forced speed link with the 6XV1830-5EH10 cable. Results may vary using other cables or using auto-negotiation rather than forced mode.

    2. I will look into the test data for information on other cables. 

    Thank you,

    Nikhil

  • 0 in reply to Nikhil Menon
    TI__Genius 11725 points

    Hi Mike,

    As mentioned Siemens cable is compliant with the  IEEE 802.cg cable spec. In terms of cable reach for other cables, we can take a look at the IL characteristics of the cable and provide and indication of cable reach. If you have a specific cable in mind, please provide IL characteristics.

    Thank you,

    Nikhil

  • 0 in reply to Nikhil Menon
    Intellectual 370 points

    So what about Belden 3076F cable - specs are available on their website.

    Mike.

  • 0 in reply to Nikhil Menon
    Intellectual 370 points

    So it doesn't make sense to me that 1Vp-p and 2.4Vp-p would support the same distance.  Surely 2.4Vp-p would cover a greater distance.  Please explain how a larger signal does not cover a longer distance.

    Mike.

  • 0 in reply to Mike Strauser
    TI__Genius 11725 points

    Hi Mike,

    Theoretically, you are correct. The larger signal should cover a longer distance. During our testing, for the cable lengths used, we have seen the cable reach of the 1Vp2p signal match the 2.4V p2p signal.

    I will look into the Belden 3076F cable performance and provide more feedback by Tuesday next week.

    Thank you,

    Nikhil

  • 0 in reply to Nikhil Menon
    TI__Genius 11725 points

    Hi Mike,

    We have published an app note describing the performance of both the Siemens cable and the 3076F Belden cable. With the Belden cable, we are able to reach 530 meters with forced speeds. 

    Please refer to Section 4.8 for the summary. 

    If I may ask, what is your application? The Siemens cable shows a much better insertion loss profile. What lead to the selection of the Belden cable?

    Thank you,

    Nikhil

  • 0 in reply to Nikhil Menon
    Intellectual 370 points

    Nikhil,

    This doesn't have so much to do with 'our application' as it does with APL being successful in the industry.  There is a belief that APL will replace Foundation Fieldbus or Profibus PA.  A lot of that has already been installed in plants using something similar to Belden 3076F.  What your data shows (and is similar to what we found with your competitor's APL Phy) is that existing installed cable will be significantly limited below the 1000m.  This may slow the adoption rate of APL for brownfield installations.

    Mike.

  • 0 in reply to Mike Strauser
    TI__Genius 11725 points

    Hi Mike,

    You are correct, the Belden 3076F and cables with similar insertion loss profiles seem to currently be limited below the 1000m. Thank you for your feedback. I hope I was able to answer your initial question about our device's cable reach. If you have any further questions, please open a new thread.

    Thank you,

    Nikhil