TIDA-00333: if three-segment long-haul network

Prodigy 80 points

Replies: 15

Views: 161

Part Number: TIDA-00333

in the documents, has two -segment, if has three-segment, if the segment3 and segment2 has same GND?

i want to this repeater used for my battery management system, BMS is master, has Vcc(5v), A, B, and GND, the battery has salve device, if the salve number is less, the BMS can provide 5V to battery RS485 component, if use this repeater, i how to deal with the 5V power supply? BMS 5V and repeater 5V, battery 5V ?

thank you very much!

15 Replies

  • Hi User5305731,

    Thank you for posting to E2E!

    How many slaves are expected on segments two and three? As bus length increases, separating grounds becomes more important to preserve signals and protect equipment.

    If either the BMS or battery circuits has an independent 5V power supply, an isolated power supply can be designed for the remaining segments using isolation transformers and transformer drivers, like the SN6505 or SN6501, as shown in TIDA-00333.

    Please let us know your response.

    Thank you,

    Manuel Chavez

  • In reply to Manuel Chavez:

    Dear Manuel,
    my BMS RS485 has 5V power supply, which can provid 5V power supply for battery(slave deveice) RS485 IC in small system, but if in big battery system, one BMS need contorl 120 battery modules, i hope every 12 battery module as one segment, total about 9 segments. if i use TIDA-00333 as repeter, if BMS RS485 5V provide power supply to every repeater? the segment2 has the same GND with repeater1 and repeater2 which if effect the RS485 communication? repeater1 provide 5V power supply to segment1 battery(from slave1 to salven), repeater 1 and repeater 2 can Simultaneous provide 5V power supply to segment2 ( from salve n+1 to slave 2n), is right?
     
     
     
    have a nice day!
     
  • In reply to fengbo.zhao:

    User5305731,

    We are having difficulty understanding your question(s). Can you provide a block diagram of what your are trying to do so we can understand better? You will need 2 independent and isolated 5V power supplies to achieve isolated RS485.

    Respectfully,

    Lucas 

  • In reply to Lucas Schulte9:

    Dear sir,

    the schematic drawing is battery RS485 interface, VCC_5V need provided by BMS RS485 VCC, if i use TIDA-00333 as repeater, if battery RS485 Vcc_5V can be provided by VS2? The  battery RS485's GND1 should be connected J2 PE?

  • In reply to fengbo.zhao:

    Hi User5305731,

    Using TIDA-00333, the 5V battery power supply will power the repeater through Vs1. Vs1 is used to create Vs2 and Vs3 power supplies. J1, J2, and J3 PE can be connected to a metal chassis or Earth Ground. This is optional.

    The 5V battery supply can be used to power all the repeaters in this system (depending on its power source capabilities), so it is okay if repeater 1, repeater 2, and additional repeaters share a common GND. Power will have to be isolated on each slave to maintain protection from ground potential differences.


    Respectfully,
    Manuel Chavez

  • In reply to Manuel Chavez:

    Hi User5305731,

    Were my comments above helpful? Please let us know if there are additional questions we can help with.


    Thank you for your time,
    Manuel Chavez

  • In reply to Manuel Chavez:

    hi Manuel,

    Power will have to be isolated on each slave to maintain protection from ground potential differences. the "Power" meaning which power?

    all repeater use the same power supply, from our BMS. but the  J1, J2 and J3 PE conneted to a metal, the salve power how to isolated?

     

    have a nice day!

  • In reply to fengbo.zhao:

    user5305731,

    The isolated power we are referring to is demonstrated in the schematic of the TIDA-00333. The SN6501 transformer driver and the transformers are creating isolated power for the isolated RS485 transceivers. Vcc1 and Vcc2 need to have isolated power supplies in order for isolation to be effective.

    Respectfully,

    Lucas

  • In reply to Lucas Schulte9:

    HI Lucas,

    Our battery RS485 schematic and system schematic as follows:

    battery RS485:

    system schematic:

    1. BMU provide 5V power supply to every repeater, if BMU‘s GND (GND1) not connect first battery GND2, if the system can work normally? if the BMU's GND)GND1) must connect GND2?

    2. Is this system can work OK?

    thanks very much!

    have a nice day!

  • In reply to fengbo.zhao:

    It appears that GND1 from the BMU is going to the "battery RS485" circuit that contains optocouplers, a RS485 device, and some passives. This circuit will need the same ground as "vcc-485" of which appears disconnected in your diagram. Where is "vcc-485" coming from?

    Respectfully,

    Lucas