[Elecraft] How does Ethernet to Serial Port device work?

[Julian, G4ILO]

Lee Buller wrote:
> 
> OK....now we are talking.  But, how does the Ethernet to Serial Port
> device work?  Of course you have to give the device an IP number on your
> network, but then how does the computer/program address the device to send
> the information to the K3  through its comm port?  Is there translation
> software to do that....or a command using the IP address?  This is
> interesting.  How does it work in the Winders program?  Somehow it has to
> have some intelligence to send the information to another specific IP
> address and then that address has to have the software to turn it into
> something usable...and visa versa.  HMMMMM.  Can anyone educate me or
> point me to the information?
> 

The program on the PC opens a connection to the Ethernet S/P device. It
sends the rig control commands to the IP address instead of to a COM port.
The commands travel along the network inside a TCP packet. The adapter
receives the packet, extracts the command and sends it to the serial port
and thence to the K3. Any reply from the K3 is read from the serial port and
sent by TCP back to the program that connected to it.

In practise, communication with a network uses different software libraries
than communicating with a serial port. So you can't just type an IP address
instead of COM1 or whatever into HRD / Logger. Either the software has to be
specifically written to work over TCP/IP as well, or you must use a separate
bit of software on the PC that talks over the network to the Ethernet S/P
adapter but looks to the program like a COM port. Then you can use any rig
control program with it, transparently.

It wasn't clear to me looking at the sites referred to whether the devices
mentioned come with such a bit of software or whether you have to buy it
separately. Some of the diagrams show two Ethernet S/P adapters, one at each
end, which would be one way to go if a bit expensive.

I think Jim asked whether this would work keying CW using DTR. I think you
would get terrible latency which would vary depending on the traffic on the
network and the CW would be horrible. I think the only way to key the rig
remotely would be either to use the KY protocol supported by the K3 (but
unfortunately not many programs) or use a remote Winkeyer. But then you'd
need a separate Ethernet adapter to talk to that.

A while ago I came across a site that had a software Ethernet to serial
server, which could be useful if your K3 is normally connected to a PC but
you want to talk to it from a different one elsewhere on the network. It
would avoid the cost of one of these adapters. But now I can't find the
site. Perhaps I imagined it.

-----
Julian, G4ILO. K2 #392  K3 #222.
* G4ILO's Shack - http://www.g4ilo.com
* KComm - http://www.g4ilo.com/kcomm.html
* KTune - http://www.g4ilo.com/ktune.html

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