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AFE031: AFE031 can support OFDM?

Part Number: AFE031
Other Parts Discussed in Thread: AFE032

"I need a device for Powerline Communication. I have shortlisted AFE031. This is for airfield lighting system, to communicate with individual lights over power line. The power line is constant current power supply based.
Also let me know if AFE031 can support OFDM? do we need to create a code for that? Or is it inbuilt? Or do we need OFDM at all? MAX2990 is offering OFDM based PLC built-in with no need to code that. There will be hundreds of lights in airfield that's why i was thinking about OFDM. i dont know if we need that or not.

The PLC will primarily to detect the fault in individual lights to the control room, and some important data in CENELAC band using G3/PRIME. Needed solutions are along with the controllers required. either MSP or C2000"

Regards,

Akshat

  • Hi Akshat,

    Our AFE031 and AFE032 PLC ICs can support OFDM, both are analog solution for PLC application (AFE03x are not SoC based PLC chip). MAX2990 is SoC PLC solution. 

    AFE031 has the full BW up to 300kHz, while AFE032 is able to cover up to 500kHz in Narrow Band PLC application. Yes, MCU is required to convert frequency to time domain data to transmit and receive. Our reference design is using C2000 processor to handle the digital part of conversion. Digital/Analog and/or Analog/Digital signal modulation and demodulation are all accomplished with MCU. For SoC PLC solution, the MCU is integrated inside of PLC chip, but it is doing the same conversion. 

    Please contact me via my internal email. We can discuss the application requirements further. As for every technical solutions, there are Pros and Cons in each approach for a given technology. As you can see, the operating temperature ranges in SoC is limited to 85C; while AFE03x can handle higher operating temperature range up to +125C with thermal shutdown temperature at 150C-160C range.  

    Best,

    Raymond

  • Dear Akshat & Raymond,

    This didn't exactly answer my queries. The queries Akshat posted was actually by me.

    I understand that C2000 processor was used to handle the digital part of conversion, but do we really need OFDM in this application? Do we need to implement that at our end?

    Regards,

    Sudhanshu

  • Hi Sudhanshu,

    I did not provide the full answer, since I saw that this was TI internal inquiry. Since this is for OFDM application, the answer to the questions depend the application requirements, which I do not have at the time. That is why I am asking if Akshat can contact me to discuss the application further. 

    Per your request, the application is for: "This is for airfield lighting system, to communicate with individual lights over power line. The power line is constant current power supply based" and do we really need OFDM in this application? Do we need to implement that at our end?

    Also let me know if AFE031 can support OFDM?

    I am still do not have all the application information, but I am going to answer some of your question, may be some speculation. Also, I have some questions:

    1. What is intended transmit and receive distance?

    2. What is transmit and receive speed? I assumed that you wound like to be close to approx. 50kpbs, may be higher.

    3. Why is the power line is constant current based? What are the power line's source current and voltage? The power line power dissipation is I2R. Unless you have very low current, constant current power line will dissipate more heat than constant voltage power line? Please explain this part. Most power line is high voltage and in AC to cut down such line losses. 

    AFE031 can support OFDM, but the transmitted BW is limited to approx. 300kHz. Beyong that, it will still work, but it will start to attenuate the signal (GBW or GBP = 670kHz). If you want to have higher operating BW, then AFE032 is the one. Also, AFE032 has slightly higher transmitting power than AFE031. But AFE031 is a lower cost and high performance PLC product. 

    The transmitting distance is a function of transmitting amplitude and current at higher frequency. 

    The transmitting speed depends on the BW and communication protocol. FSK or S-FSK communication method is likely too slow in speed for your application (<2kbps or so). You may need OFDM communication modulation, so that you can send more bits of information at a time. 

    Do we need to create a code for that? Or is it inbuilt? Or do we need OFDM at all? 

    Yes, you will need to a create a code for that. We do have some OFDM sample codes for C2000 processor, but you have to request for it. The software code is similar to ethernet's Open Systems Interconnection (OSI) Model, except you may need the Physical layer for your application. Since this is unique application, you may create your own proprietary communication protocol to modulate and demodulate the data over the transmission line. It is also possible to find similar open source codes for the application. For these specific questions, you may ask software engineers. 

    Please let me know if you need further questions. 

    Best,

    Raymond

     

  • Dear Raymond.

    For your understanding, the topology of airfield lighting system is as given in link below.

    https://www.google.com/url?sa=i&url=https%3A%2F%2Fdownload.atlantis-press.com%2Farticle%2F25890443.pdf&psig=AOvVaw0LjPgXW8gc4exQTAGvT0Zy&ust=1593752002681000&source=images&cd=vfe&ved=0CAkQjhxqFwoTCID4lITjreoCFQAAAAAdAAAAABAD

    Traditionally the Airfield lights consist of halogen bulbs and applying voltage based system was not feasible due to voltage drop occurring at each individual lamps resulting in non-uniform brightness across the airfield. To solve this, a constant current based system was introduced to have uniform brightness across the lamps and need to layout expensive long distance parallel cabling system based on constant voltage system with constant current thyristor based power source between 2.8A-6.6A with voltage going up to 10KV at 50Hz depending on lights in series . These are now to be replaced with LED based system, without changing the layout of the airport lights.

    To communicate with the individual lamps/led drivers from ATC towers, we need a power line communication based system in where the master module is placed after Constant Current Regulator (CCR) and each lamps would have slave module (after isolation transformer) which responds to the master about its status and other information is passed whenever required. There are typically hundreds of lights in a single loop communicating spread over 2-5-10 Kms (not sure) with a single master over PLC.

    Hope this gives you information about what do we need to do. The BW of 300khz seems fine for this application. But the confirmation we need is that if AFE03x capable to deliver what we intend to do over the constant current power line loop. Is this AFE03x capable of doing multi-hop communication if specific lamp is not reachable directly over the power line? Is OFDM necessary here?

    I had requested for the PLC code (G3 & PRIME) for C2000 already, but don't know why my request is not getting though. Requesting you and Akshat to look into this and approve the request for this.

    Regards,

    Sudhanshu

  • Hi Sudhanshu,

    Can you send me a friend request via E2E forum? Once we established the contact, we can discuss the application via private message. 

    Best,

    Raymond

  • Hi Sudhanshu,

    I have replied your inquiry via private E2E message. Shall we close this inquiry?

    Best,

    raymond

  • Yes Raymond. Please delete this inquiry from the system. We will talk over private E2E message.


    Regards.