Serial to ethernet device?

Posted by: drakino

Serial to ethernet device? - 05/06/2008 18:39

My googlefu isn't working well, too many generic terms I suppose. Anyhow...

Does anyone know of a device to hook onto a serial device, and then allow it to be talked to over ethernet? I'm imagining a little box with a serial port on one side, ethernet on the other, and intelligence in said box that lets it grab a DHCP IP, and listen for telnet connections or something over TCP/IP that are then relayed via serial to the serial device attached.

To explain what this is for, I have an orb at work. The goal is to have it change color to indicate build status. The device normally uses a pager network to be told to change colors, but this has two problems. One, it's slow, and can take 5-15 minutes to change from when the command was sent. Two, the ability to send custom color commands over the network is unavailable till september due to some change on their side. So the plan is to buy the serial developer board that hooks into the orb and gives it a serial port. Builds are run on servers tucked away in our datacenter, so having it serially attached is no good if it is going to be on someones desk. Hence the idea for lan, plus having it talk over the network will be easier to integrate into the build system then serial communications.

Thanks in advance
Posted by: tman

Re: Serial to ethernet device? - 05/06/2008 18:58

Many many many devices do this. I've used Lantronix devices before. Both embedded and standalone boxes. The MSS100 would be one of the standalone ones.
Posted by: Boelle

Re: Serial to ethernet device? - 05/06/2008 19:01

i have found such a device, but it's located in denmark
Posted by: andym

Re: Serial to ethernet device? - 05/06/2008 19:06

Moxa or Rocketport will do exactly what you're after. I've used both in mission critical applications and they both perform flawlessly. They scale from single 232 boxes to 16 and 32 port 232/422/485 devices.
Posted by: andym

Re: Serial to ethernet device? - 05/06/2008 19:22

Originally Posted By: drakino
My googlefu isn't working well, too many generic terms I suppose.


They're usually called serial device servers. A quick google returns the lantronix and moxa websites in the first page.
Posted by: wfaulk

Re: Serial to ethernet device? - 05/06/2008 19:24

Also "console servers".
Posted by: andym

Re: Serial to ethernet device? - 05/06/2008 19:51

Originally Posted By: wfaulk
Also "console servers".

Which reminds me, Black Box do them as well.
Posted by: tfabris

Re: Serial to ethernet device? - 05/06/2008 20:02

A simpler option:

If you've got control over the physical wires that run to the orb, control over any patch panels between you and the orb, and an extra ethernet port at your desk, just get those little plugs that you usually get with Cisco routers and such, that will pin-out and RS232 plug into an RJ45 plug. Put one at both ends of the connection, and use an actual serial port on your PC to do the updating.
Posted by: andym

Re: Serial to ethernet device? - 05/06/2008 20:04

i seem to remember the empeg guys having a broken build beacon which was one of those rotating red lights you used to see on police cars before they got all fancy and starting using LEDs.
Posted by: wfaulk

Re: Serial to ethernet device? - 05/06/2008 20:24

Oh, from my list of bookmarks that's not been updated in a while:

Avocent
Lantronix
MRV
WTI

Of those, I think Lantronix has the product you want. They even have WiFi ones.
Posted by: peter

Re: Serial to ethernet device? - 05/06/2008 20:34

Originally Posted By: andym
i seem to remember the empeg guys having a broken build beacon which was one of those rotating red lights you used to see on police cars before they got all fancy and starting using LEDs.

It worked over X10: an X10 controller on a serial port in the server room, and an X10 mains relay in the ceiling above the red light -- so it didn't actually send RS232 over powerline. The light itself came from a disco supplier.

Peter
Posted by: andym

Re: Serial to ethernet device? - 05/06/2008 20:40

depending upon the distance you'll probably have to use 422 line drivers to maintain signal integrity which is likely to be similar in cost to a device server. It also assumes you have spare copper between your datacentre and your office, and also whether you've got a spare serial port on your box.
Posted by: tman

Re: Serial to ethernet device? - 05/06/2008 20:46

Its more of a project than just plugging in the converter but an ethernet enabled development board + multicolour LEDs + sphere would be more flexible. You're already bypassing the main feature of the Orb where its connected to the pager network.
Posted by: mlord

Re: Serial to ethernet device? - 05/06/2008 21:19

Originally Posted By: drakino
Does anyone know of a device to hook onto a serial device, and then allow it to be talked to over ethernet?

If it's a one of thing for home use, then your empeg can do this for you.

Just install telnetd and ckermit on the empeg.
Voila .. instant one-port terminal server.

If you want it more automatic than that, then create a terminal-server user for /etc/passwd, and set the shell to be /bin/ckermit and create a ~/.kermrc file with the appropriate defaults.

Cheers
Posted by: drakino

Re: Serial to ethernet device? - 05/06/2008 21:39

RE: RS232 over cat-5. More trouble then it is worth. The server doesn't have a serial port, the build system doesn't know how to speak serial, and wiring it would need to be changed frequently enough for the nearterm to make it a hassle, including an upcoming office move. Plus, if we end up adding a few in various places, then multiple special runs of cable have to be managed.

RE: Building the full color changing device. The orb is already a piece I have, and was hoping to just use the pager network with it. But then the problems of the dev side being off and also the time delay issues came up. The device is pretty nice in the flexibility it offers as far as color range, blending between multiple states and such. Might investigate building one if we do want more then just this unit.

RE using an empeg, I'd like to keep that in my mlord dock on my desk playing music and not the final place the orb will end up :-)

Thanks everyone for the info and ideas. I'll probably look at the premade solutions for now to integrate into this, as it's mostly just a side project to do when idle at work.
Posted by: sn00p

Re: Serial to ethernet device? - 07/06/2008 06:45

Shamless plug coming up....

http://www.componentbin.com/index.php?location=shop&category=37&action=viewcategory

Our smart module can do this, infact I've got code for it (would take 5 mins to get up and running on that particular module). I ran out of serial ports for some ATE stuff I was doing for a product we make for a scientific company, so I resorted to doing serial<->ethernet. Worked very well.

Ignore the out of stock..it's not actually true in reality.