TV RS-232C Control Over Ethernet

[Scud]

Hi guys;

I was just wondering whether it is possible to control my TV's through the RS-232c port on the back. The problem is, i have not allowed for RS-232C cables in my wiring and therefore makes it a little bit hard. I have however ethernet cables behind my TV's. Is it possible to send the commands via ethernet and have them converted to RS-232c so my TV can respond?

Thanks in advance,
Scud

 

[Sacedog]

To answer your first question, it depends on the TV. Some TVs publish their serial protocol, and some don't. Also, that port is only for "service" on certain TVs, while others truly do allow for serial control.

The answer to your second question is yes. You have a couple of options. First, if you have an extra ethernet cable run, you coudl simply wire DB9 connectors on the end of an Ethernet cable on both ends of the run. I did this in my house, and it works great. Your other option would be to purchase a serial over ethernet device, such as one from Digi or Startech. I have not used these types of devices, so someone else might want to chime in on their use. I'm not sure if they just easily add the DB9 connector on either end, or if they allow your serial communications to traverse your ethernet network.

 

[WayneW]

Is it possible to send the commands via ethernet and have them converted to RS-232c so my TV can respond?

Sure, search here for Lantronix or Quatech (among others).

 

[Scud]

The majority of them are LG tv's and the port says control and service. So I'm assuming it allows control. I have the ELK M1, is it then possible to connect it up to this and get the M1 to send commands to it?

 

[drvnbysound]

I'm not sure if they just easily add the DB9 connector on either end, or if they allow your serial communications to traverse your ethernet network.

Generally, its the latter - where the device is actually IP addressable, commands are sent to it via IP stream and converted at the device to a serial command over the DB9 connection.

 

[drvnbysound]

The majority of them are LG tv's and the port says control and service. So I'm assuming it allows control. I have the ELK M1, is it then possible to connect it up to this and get the M1 to send commands to it?

The LG protocol is published in the manual (on the CD that came with the TV). If you no longer have the disc that came with the TV, you can DL the manual from the LG website. I dont know of LG doing various protocols for different models, series, or yrs of manufacture, but I assume its possible so I would definitely suggest to get the protocol for your particular model - especially if you are sending it discrete commands directly.

I recently connected a PC to one of my LG TVs just to test this out as a proof-of-concept for myself. The way the LG documentation is written had me confused about the actual structure of the commands to send, but after playing with it a bit it was easily figured out. This may simply be because my lack of serial protocol knowledge and thus lack of interpretation skills.

 

[electron]

What distance are we talking about here? If it isn't too far or a high speed port, I would try the DB9->RJ45 adapter approach. Chances are that you can get away with using just 3 wires of your cat5 drop (so you can still use it as an Ethernet run, etc.) since most simple serial devices only use TX,RX and the GND pins.

If that won't work, then a cheap RS232->Ethernet adapter would be my next choice, using a cheap Lantronix found on eBay like others mentioned.

 

[gatchel]

I might have some Lantronix units available in the near future. I'll post them in the classifieds when they are ready.

 

[znelbok]

I have cat5 with serial to my LG TV.

It is not Ethernet, but RS232C. It is about a 25m run and there are no problems at all.

I have not done it with the M1, but using a serial expander, I cant see why you could not send a command over the cat5 to the TV. The LG protocol is very simple, but very comprehensive (the best out there for TV's).

Alternatively you could look at something like the global cache GC-100, which is Ethernet to IR.

Mick