Topic: RS 232 to ethernet adapter, five years later

[DaleReid]

I have been thinking it is time to do some final station work, and one thing I need to do is get a sensor's rs232 data about 200' into my house where I can use it.  The first attempt was back about 2020 and some of the suggested links I looked up here are dead or one I tried back then was indecipherable, despite one member saying he got it to work, finally.

Now I find newer stuff on Amazon and eBay.  One that caught my eye was a RS232 db 9 male/female to an ethernet RJ45 socket.  It seems like this should work.  There are several brands available for not too much money.

Another attractive but more expensive ($50 vs $9) option which also requires power at the site is a little box that behaves like a web server, even, in addition to taking serial data and sending it out over the ethernet where either PuTTY or such can see it, or even use ModBus to see  it coming in. 

Has anyone done the cheap and simple, using a pair of the little converters to send data over the longer ethernet?

Another option would perhaps convert the rs232 to the rs 486 which can run the distance at lower baud rates. 

Just searching for hints and ideas as the ground thaws out and I can begin to tunnel wire out to the sensor site.
Thanks for experience reports and suggestions.  Dale

[TheBushPilot]

Dale,

What sensor are you trying to get into your house over RS-232?

Not sure if you have power where this sensor is located or not (12V) but they make many low power serial to ethernet and serial to wifi adapters that are pretty straight forward to configure and get going. My personal favorites are ones made by PUSR who manufacture all kinds of converter electronics. Their multi port RS-232/485 serial server devices are used by the NYS Mesonet.

Their USR-W610 is a serial to wifi/ethernet converter that has about all the serial configuration you would need for your sensor. This may be wired with ethernet or transmit over wifi to your LAN with your own selected SMA connector antenna. At 200 ft you could probably use a couple dbi directional yagi and keep the connection simple. Your LAN will assign the converter its own local IP address and you can access it with whatever software you have.

The USR is transparent bi-directional serial communication. The alternative which is for extremely low power applications (and in use in my friends weather station down in Florida to transmit his data) is a US Converters S2W232E-ESP32 RS-232 Wifi Adapter. This is a great little device that too has decent range with the right RP-SMA connector antenna. The only caveat here is it is uni-direction communication. A DTE/DCE toggle switch on the back of the device selects which direction communication flows. So if your intentions are only to transmit data to the sensor with no need to communicate back to it, this device would be a good option as well.

I'm not sure how you intend on enclosing everything but with the converter in an enclosure you can get one of those DB-9 solder connectors and have the sensor cable directly break out to that connector and have it plug straight into the converter to keep things simple.

The USR-W610 is around $50 on amazon, but I have found them for around $20 on eBay used.
The S2W232WE-ESP32 is around $70 from US Converters. Note that I had firmware issues with this converter and it locked out the transmitter due to this so you have to do a firmware upgrade. I have the email on how to do with from the manufacturer if you end up going with this one.


Cheers

[mcrossley]

An RS232 to Ethernet adapter with PoE input to power it sounds like it might work? The StarTech.com 1 port is an example a quick search threw up, but it's not cheap.

[weatherdoc]

Not sure what device you are trying to connect to, but I have a 100 ft ethernet cable buried in my back yard to power a camera using PoE. The PoE switch is a BV-Tech PoE+ Gigabit switch - $27 on Amazon. You can easily run a 200 ft ethernet cable on the PoE switch. The cable was a bit pricy because I purchased one that was suitable to be buried outdoors.

[Tln7559]

Oldfashioned, but if you have a remote device with RS232-interface and want to communicate over longer distance over cable, perhaps at either side of the channel a simple modem could do the job, although effective speed will be far below Ethernet-performance.
Cabling from device to house is simple enough a 2wire-telephone-line.
Changes the question how to interface at the computerside, because RS232 from the modem no longer a common interface for modern computers.
RS485 is also suitable for communication over long cabling, but beware that speed on an RS485-interface is inversely related to length of the cable, but usually better than modem-speed as hinted above.

[DaleReid]

Thank  you for ALL the suggestions.
I saw the item that BushPilot refers to and looks good, but a bit more expensive and perhaps some overkill.  This is all playing out yet.  I may have a source of power as noted, but will have to see if I can lay another cable in the same trench to give me enough.

For enclosure aat the out of doors end, I have a Campbell sealed enclosed equipment housing that will be more than big enough.  My wife hasn't seen what this might look like, ahem.

But the back yard is where I do my stuff so at my age she humors me.

I'll be putting up a Campbell CS-110  electric field detector which needs some power, too.  The output of the datalogger is only the rs232,  unlike some more recent dataloggers which already have an ethernet connection or the possibility of attaching a converter right to the datalogger.

I'm sure this won't be NWS quality but it has been a decades long project to be able to do a electric field strenth monitor and if I don't get it done now, I may never do so. 

I appreciate ALL the ideas and as usual, those who have done similar things or have engineering/science background are aware of pitfalls that I am not.
Dale

[Wooks61]

  My wife hasn't seen what this might look like, ahem.

But the back yard is where I do my stuff so at my age she humors me.

 

[TheBushPilot]

Thank  you for ALL the suggestions.
I saw the item that BushPilot refers to and looks good, but a bit more expensive and perhaps some overkill.  This is all playing out yet.  I may have a source of power as noted, but will have to see if I can lay another cable in the same trench to give me enough.

For enclosure aat the out of doors end, I have a Campbell sealed enclosed equipment housing that will be more than big enough.  My wife hasn't seen what this might look like, ahem.

But the back yard is where I do my stuff so at my age she humors me.

I'll be putting up a Campbell CS-110  electric field detector which needs some power, too.  The output of the datalogger is only the rs232,  unlike some more recent dataloggers which already have an ethernet connection or the possibility of attaching a converter right to the datalogger.

I'm sure this won't be NWS quality but it has been a decades long project to be able to do a electric field strenth monitor and if I don't get it done now, I may never do so. 

I appreciate ALL the ideas and as usual, those who have done similar things or have engineering/science background are aware of pitfalls that I am not.
Dale

Dale,

If I recall you said you have a Campbell Scientific CR3000 data logger. You can get an ethernet peripheral for that data logger if you don't already have one and access the CS-110 via TCP over your LAN with the serial to ethernet/wifi converter. Then you would be able to read the sensor and store the data to local tables in the data logger as though it were a typical hardwired instrument.

Reading further on the CS110 product page, it looks like it has an embedded CR1000 data logger? You should be able to communicate with it using pakbus from your CR3000 very easily.


Cheers

[DaleReid]

the CRs have a serial output and IF you have an adapter, like an NL115 or so, you can plug in ethernet and indeed communicate that way.

The problem with the CR1000 is that it does not have this capability, nor does it have room enough in the enclosure to add this on to the unit.  The typical install with a 1000 has the brains of the  unit in a sealed stainless steel chassis, which plugs into the back of the corresponding wiring panel, and the ethernet adapter plugs into that panel.

The CR1000X has built in ethernet, but again the wiring panel provides that functionality.

So as far as making the CS110 able to communicate via ethernet, I'd have to find a compatible rs232 to ethernet adapter of some sort, and plug that into the  unit.  Of course that would be super.  I have the two CR3000s and a couple CR1000s with the ethernet adapter from CS and it works superbly.

As an  update, I did find a simple little rs232 to CAT5 cable adapter, plugged one end in at the unit, another with test lengths of 10, then 50' CAT5 and then reversed the connection to plug into a USB port connector at the computer.  That gives, so far, flawless connection, data monitoring and downloads of data, but only at 115k baud, not true ethernet speed.  And I cannot use other ethernet type communications (connect from any computer on my LAN, Weather Display via ModBusPak, etc) which would be the ultimate.

Still workng for the final solution, but these little gizmos for $9/pair from Amazon have given me much more flexibility in positioning and length of cable run.  I don't know how they work, but I am pretty sure this is just using CAT5 as an extension cable, if you will, rather than making some sort of ethernet out of it.

Your ideas were spot on, if it weren't for the lack of wiring panel inside the CS110 and no where to stick a Campbell Scientific adapter on the thing.  But you've got me thinking of wome way to make an adapter at the sealed box to actually look like an ethernet termination.
Dale