[time-nuts] Serial port server .. any interest in a write up on using ?

[Ed Palmer]

I've played with a Lantronix single port server and a Digi 16 port 
server with no problems for simple COM port emulation.  But I wonder if 
they would work well with an NTP server.  Has anyone tested that?  Is 
the network delay a problem due to either amount of delay or variation 
in the delay?

Ed


On 5/22/2012 12:51 PM, Pete Lancashire wrote:
> Some comments
>
> The make and model I'm using is
>
> Digi www.digi.com
>
> http://www.digi.com/products/serialservers/portserverts#overview
>
> I've used the 1, 4 and 16 port. The 1 and 4 are the same design.
>
> USB
>
> There are USB serial port servers, I have one that is 4 ports. But
> like anything USB it requires the computer to be close. For me I have
> two locations where my gizmo's are not near the PC. The other is at
> times I want to be able to run Lady Heather or Trimble Studio from my
> Laptop which maybe out on the porch while having a beer and operating
> the BBQ :-)
>
> Group buy
>
> The model I've been using is still made but even the 1 port model is
> over $100. The 4 port model shows up on the E quite often
> and I've been able to get them for as little as $20. The 16 port model
> was $5 at a local used PC store.
>
> Cards (Internal)
>
> For me pretty much the same as USB, and the other for me is the PC I
> have on the bench has only 2 short length PCI slots.
> One is taken up with a GPIB card an the other a data acquisitions
> card. Another is I have two benches. With a network attached
> setup I can access my serial stuff from either bench.
>
> This is my setup your mileage may very like in many setups.
>
> Also past experience has not been pleasant with these things. If your
> 100% Microsoft and never update past XP you may be
> OK
>
> Other makes, Lantronix, Cyclades, etc.
>
> Other then Cyclades 48 port servers, Digi is the only other vendor
> I've worked work. Hence not disqualifying anyone else
> just what I've used.
>
> Terminal servers are simple boxes.  You just Telnet to the port.
>
> Some are, some like the current generation Digi's go beyond that. For
> example the software that makes a port on the
> Digi look like a COM (uSoft) or TTY (*nix) port. They even do things
> like create port tunnels, where a serial port on two
> box 'look' like the same port. One thing I like with the ones I have
> is you can for example set port 1 to emulate a COM
> port, port 2 to respond as a telnet session, port3 to only use SSL so
> you can safely use it over the Internet, etc. And if
> you really careful, you can have multiple network sessions telnet for
> example to one serial port. Something I've not
> yet tried.
>
> Cost
>
> Pretty much how good you are at finding stuff, where you live, etc.
>
> My 16 port unit was $5, the most I've paid is something like $40 (1/3
> of it shipping) for a 4 port models.
>
> I will be adding a wiki to my yet to be developed website and will
> make a page on what I've implemented, I'd love
> to see what others have done with different makes and models,
> specially in emulating COM/TTY ports.
>
> Before that I'll write up a short summery for this weekend.
>
> -pete
>
>
>
> On Mon, May 21, 2012 at 7:55 PM, Pete Lancashire
> <pete at petelancashire.com>  wrote:
>> Like many time-nuts I have quite a few devices that communicate to the
>> outside world with a serial port. And like many I have more then one.
>> In a past life I use to have to connect to sometimes a 100 RS232 in
>> one location. A popular device is called a terminal server or
>> concentrator. They would take from 1 to 48 RS232 ports on one side and
>> let you talk to them via an Ethernet interface. I so far have twelve
>> RS232 ports in use.
>>
>> Now that the need for such devices has diminished, these terminal
>> servers are showing up, sometimes for pennies.
>>
>> One brand and model Digi's TS family of models I and have verified
>> they work with Lady Heather and Trimble Studio on a Windows XP PC.
>>
>> Digi offers for free a program that makes each RS232 Port look like a
>> COM port, and after configuring the terminal server, and this driver,
>> you just just fire up Lady Heather pointing to the correct "COM Port".
>>
>> Other RS232 ports on the terminal server can either be COM ports, or
>> one can be connected to via Telnet of for security SSH. For example I
>> have an Odetics on one port
>> and I just enter telnet ts4a (the DNS name I gave one of the terminal
>> servers) 2003 (the IP port associated with the third RS232 port).
>>
>> So if this is of interest to anyone I'll go into more detail, models, setup etc.
>>
>> -pete