ST7580 Maximum Devices on the Power Line

astangeland · ‎2013-09-19

Posted on September 19, 2013 at 22:50

I need to transmit to about 500 receivers, each one needing ~1.5kbps of data. So I need ~750kbps of total bandwidth. Can I use one transmitter per 5 receivers so that I have enough bandwidth (1.5k*5 = 7.5kbps which is less than the 9600bps of a single ST7580)?

Each transmitter and set of five receivers would be tuned to their own frequency. So I would have 100 transmitting devices each at a different frequency, and 500 receivers (one listening to each frequency). Will the different ST7580s be able to communicate at 100 different frequencies simultaneously on the same line? If not how many different frequencies could be used without them interfering with each other? (This would be in the FCC range for a US 110V application.)

With 600 devices connected to the line the capacitive loading of all of the frontend filters is going to add up. Will this cause a problem for communication? If so how many ST7580s devices could be placed on a single line without issue?

#st7580 #support

Nickname14006_O · ‎2013-11-19

Posted on November 19, 2013 at 21:49

The ST7580 is designed for meter reading, so there is not much of a limit on how many can be on a single power line or other wires.. However, in the normal case, if one hears another 'speaking' it typically waits. In your application, it would seem like many (100) are transmitting at the same time. You will therefore have to design filters to isolate the signal energy in each of the 100 communications channels that you have defined, from getting into the other channels. The loading of the coupling circuits should not really be an issue, power line impedances are quite low anyway. You mentioned a one to five relationship. Usually it is done in a round robin manner. I won't say it can't be done parallel with some firmware you would write, but there is no advantage for bandwidth. To help us better evaluate your communication system requirements and see how we can economically provide a solution, please contact your local ST sales person or ST rep who will connect you with the right engineers to help you get started, referencing this topic.

Thanks!

registration · ‎2014-03-01

Posted on March 01, 2014 at 21:09

Dear Andy,

Sorry to bothering you, but I did not get any reply from the ST support about the ST7580 ''drivers''. Do you know where is it available or did you write it on your own?

Thank you in advance,

Daniel M.