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I have a PA system that has 60 devices of which 57 are indoor wireless modules. They need a USB-a to b cable to program, and according to the manufacturer there is no way to program it over wireless. The Principal changes the class types and schedules every quarter so there are rooms that need schedules updated every quarter. The only way to change them (according to the manufacturer) requires me to spend several hours of climbing ladders opening ceiling tiles and programming each device individually.

I want a quicker solution but the manufacturer doesn't have one. I wondered about a wireless USB-b adapter that would use a receiver and remove the need for a ladder to talk to the unit. I did find an arduino setup that would connect the unit to the network, but there are "Malicious kids" on the network so that's out of the question. The search was fruitless so I turned to other ideas. I remember in my alarm tech days there was a serial connector that went through Ethernet and used a com port to communicate with the laptop. the PA devices also talk through com ports so I thought if there was a way to convert the USB-b cable to Ethernet I could run them to the network room and I would be set. There are adapters that go from USB-b to Ethernet but they cost around $50 a piece and I would still need to run the Ethernet. There are also USB-a to Ethernet and USB-a to b adapters that are significantly less expensive, but it adds potential failure points and seem to complicated to suggest to the boss. At this point I figured why not just make one, so i started looking up the pinouts. It seems simple enough but as the longest run would be about 80 ft. I wonder about the signal strength and interference.

So here are the main questions.

  1. Are the communication protocols too different between USB and Ethernet?
  2. Would the com ports act the same through Ethernet?
  3. Is there any other reason this wouldn't work?
  4. Is there any simpler solution that I haven't found?
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  • Why keep these wireless models if you're just going to wire them up after all? Also, can't you password-protect your Arduino solution? – Spiff Jan 2 '20 at 21:49
  • Would installing separate USB extensions reaching to the edge of the tiles, or dangling over, be of help for the worst cases, i.e. least accessible or most frequently updated? Admittedly, that would bring access closer to the malicious actors. sigh – DrMoishe Pippik Jan 2 '20 at 22:28
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Short answer: yes. The protocols are very different.

However, the reason for a lot of hardware requiring USB to be programmed is because the device emulates as a serial device, and communicates with the configuration software via RS232 or RS422.

If this is the case, one alternative could be to have Serial to Ethernet adapters. I also know that there are USB to Ethernet adapters if this is not the case.

To summarize for your specific questions:

  1. Yes. Too broad of an answer to get into details.
  2. In theory, yes, if endpoint communication is handled correctly.
  3. Running serial over Ethernet with proper encapsulation should work fine, provided there is only one client connected at the time. Other than that, it's mostly down to hardware. I know Moxa has a lot of quality gear for this type of work.
  4. None as convenient.

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