Ethernet Contact Input / Relay Output - Page 1
Forum section: electronics / general

author: David_AVD
author_rank: Super Contributor
timestamp: February 05, 2015, 06:48:44 am
content: I have need to send a contact closure over an Ethernet network to a remote relay. The input is an ordinary switch and the output will activate an alert buzzer.If I *have* to, I can also use something with RS485 I/O as I already have contact-to-RS485 and RS485-to-noise boards.Looking to buy something off the shelf, so no Arduino, pi, etc solutions please.

author: SL4P
author_rank: Super Contributor
timestamp: February 05, 2015, 07:01:06 am
content: Probably cheapest & simplest route is the smallest ethernet-enabled Arduino with a minimal relay board (or a transistor & relay!).If you're in Melbourne SE suburbs (Glen Wav) - I'll gladly help you out - and I have all the parts laying around to get you proto up & running. PM if interested. it should take a couple of hours max.

author: David_AVD
author_rank: Super Contributor
timestamp: February 05, 2015, 07:10:40 am
content: Was really looking for a pair of small ready made boxes (or DIN rail cards) that I can give to the installation guy and have it "just work".I'm in Brisbane but will keep you in mind.

author: SL4P
author_rank: Super Contributor
timestamp: February 05, 2015, 07:38:00 am
content: I used to have one of these - but after a quick trawl around the web, I can't see any other off-the-shelf solutions that suport physical buttons (they all have web-based/iPhone applications).https://www.iobridge.com/The only weaknesses of iobridge in this application - are $price for a simple solution, and it is 'cloud' based - requiring a web connection to their servers to act as the arbitrator between modules.With two of these units and a relay driver - it is fairly trivial to set up a button in one location and a relay in another - but it is an unnecessarily complicated & expensive way to go.Arduino (or any micro with an IP stack) + shield + a bit of code = cheap and cheerful - and you have control of the whole system from end to end - forever.

author: dave_k
author_rank: Frequent Contributor
timestamp: February 05, 2015, 08:19:02 am
content: Quote from: David_AVD on February 05, 2015, 06:48:44 amAdvantech make a decent range of both ethernet and serial I/O devices. I have used them before on several projects, they seem decent and reliable.http://www.advantech.net.au/products/Remote-I-O-Modules/sub_1-2MLCJF.aspx?utm_source=home&utm_medium=tab-link-category&utm_campaign=trackhomelinks&utm_content=%2Fproducts%2FRemote-I-O-Modules%2Fsub_1-2MLCJF.aspx

author: David_AVD
author_rank: Super Contributor
timestamp: February 05, 2015, 08:26:37 am
content: Yeah, anything cloud based is definitely out.I'll check out those Advantech modules. A lot of the ones I've found so far are switch or relay to "virtual something" and don't seem to be able to be used as a simple pair.

author: SL4P
author_rank: Super Contributor
timestamp: February 05, 2015, 09:10:22 am
content: Yep - exactly.Most are ''port extenders'' to put a pc (or web page) driven remote serial or I/O port at the far end, but very few (if any) offer a dedicated pair of peer-to-peer interface for contact closure.I have certainly used a few differentserial-net-serialproducts, but nothing that I've seen withcontact-net-contact

author: Kjelt
author_rank: Super Contributor
timestamp: February 05, 2015, 11:37:33 am
content: Have a look at the Global cache products, usually used for hometheaters and av installs, does what you want and reasonable price.Check out the GC100 products with relay or the very cheap Itach IP2CC.Good thing is that they have a document for the API so you can use 3rd party SW or write your own software.http://www.globalcache.com/

author: Richard Crowley
author_rank: Super Contributor
timestamp: February 05, 2015, 11:54:52 am
content: There appear to be a wide variety of commercial products that do precisely "contact closure over ethernet".Of course, being industrial products, they bear an industrial-strength price.Assuming that when you say "ethernet" you mean routing data packets through one or more switches, hubs, etc.Otherwise, if it is a single-hop from point-A to point-B, some people simply use the un-allocated pairs of the Cat-x cable.There are also gadgets that "break-out" the "spare" pairs from a Cat-x cable in ethernet service (which uses only 2 pair of the 4 pairs)

author: SL4P
author_rank: Super Contributor
timestamp: February 05, 2015, 08:04:23 pm
content: Quote from: Richard Crowley on February 05, 2015, 11:54:52 amFair point - I made the assumption that the OP wanted to use remote 'networked' operation - using some existing network/internet TCP/IP infrastructure.You're right about the availability of industrial style devices, but the cost & wasted resources (enclosure, extra unused I/O etc) to implement them are just a bit OTT for a simple remote contact closure (in AND out).Global Cache seemsto have half the solution(their web info is near useless)http://www.globalcache.com/products/itach/ip2ccspecs/seems to address the IP to Relay, but I didn't see a contact-closure to IP device - andno obvious mention whether units can talk directly to each other, or require a host controller...?

author: David_AVD
author_rank: Super Contributor
timestamp: February 05, 2015, 09:25:31 pm
content: Yes, I want an Ethernet (network) solution, not a CAT5 cable solution.The end points are serviced by CAT5 Ethernet IP connections, but separated by various network transport/routing possibly including fiber.I can ask for a pair of IP addresses and have them provide a route between them.

author: David_AVD
author_rank: Super Contributor
timestamp: February 05, 2015, 09:27:58 pm
content: Quote from: Kjelt on February 05, 2015, 11:37:33 amThere's no software required / wanted apart from maybe a configuration web page. Purely a switch closure on one end point and a relay on another.

author: SL4P
author_rank: Super Contributor
timestamp: February 05, 2015, 11:54:03 pm
content: Yep - I'm still with you to do a quick & easy Arduino/Atmel/PIC solution.Arduino will be fastest with off the shelf parts and - cheap.Go to PM if you want to discuss.Think about a budget - remember uC module, ethernet interface, relay board, enclosure, (power supply? plug-pack?) and a bit of code.By definition it will include a (USB/serial/telnet) command line and/or web interface for LAN/configuration.(and surprisingly the enclosure can take 30% of the hardware budget in some cases.)

author: Rasz
author_rank: Super Contributor
timestamp: February 06, 2015, 12:35:41 am
content: https://forum.openwrt.org/viewtopic.php?id=54722

author: sca
author_rank: Regular Contributor
timestamp: February 06, 2015, 12:41:05 am
content: Something from Lantronix?http://www.lantronix.com/device-networking/external-device-servers/intellibox-io.htmlfor example?sca

author: David_AVD
author_rank: Super Contributor
timestamp: February 06, 2015, 12:54:09 am
content: Quote from: Rasz on February 06, 2015, 12:35:41 amThat seems to be exactly what I'mnotlooking for. I only scanned the thread but only saw mention of SMS or web page triggers (not an end to end solution).

author: VintageTekFan
author_rank: Regular Contributor
timestamp: February 06, 2015, 01:04:43 am
content: Something like this?:http://www.relaypros.com/Relay/Device/MirCR120_MCNET

author: SL4P
author_rank: Super Contributor
timestamp: February 06, 2015, 01:38:38 am
content: Quote from: sca on February 06, 2015, 12:41:05 amLook interesting, but I still didn't see anywhere that units can talk to each other... ?They expect an intelligent host or user to initiate the port activity...http://www.lantronix.com/pdf/IntelliBox-IO_UG.pdf

author: SL4P
author_rank: Super Contributor
timestamp: February 06, 2015, 01:42:05 am
content: Quote from: VintageTekFan on February 06, 2015, 01:04:43 amwww.relaypros.com/ALMOST PERFECT !Caution- they say no STATIC IP- which suggests they 'phone home' to an arbitration server - like iobridge...- or use broadcast packets to locate each other - which voids te ability to p[ass through routers during auto-discovery...

author: David_AVD
author_rank: Super Contributor
timestamp: February 06, 2015, 02:22:02 am
content: Quote from: SL4P on February 06, 2015, 01:42:05 amYeah, as far as I know the IT infrastructure will require that the end points are static IP.Thanks for the suggestions guys. At least I know what's out there and some better search terms.

author: SL4P
author_rank: Super Contributor
timestamp: February 06, 2015, 02:31:46 am
content: Visual summary - over routed TCP/IP networkIt may be worthwhile to add a backchannel at no extra cost - to indicate the actual relay state.

author: Paul Moir
author_rank: Frequent Contributor
timestamp: February 06, 2015, 04:59:11 am
content: If you just need a one-off, what about a cheap Koyo PLC and Ethernet (modbus over TCP) module?Disadvantages: ~$350 all told, somewhat large. I never trust PLC's security. May not be the sort of thing you're looking for?Advantages: 6 relays, inputs, some logic if you need it, built in power supply if one isn't available, regulatory approvals.

author: SL4P
author_rank: Super Contributor
timestamp: February 06, 2015, 05:18:41 am
content: Well that was exciting...Yet another uC option that you can consider if rolling your own.Seems only missing the pushbutton and the wired ethernet and relay, but otherwise - a neat solution.Easy to add those - but the rest is what has been proposed already - several times.Back to step 1.

author: David_AVD
author_rank: Super Contributor
timestamp: February 06, 2015, 07:43:03 am
content: Looks like I've found a solution:http://oceancontrols.com.au/CBW-040.htmlandhttp://oceancontrols.com.au/CBW-060.htmlJob quoted !

author: SL4P
author_rank: Super Contributor
timestamp: February 06, 2015, 08:23:27 am
content: Ocean are a really good bunch.Ive purchased a few things from them in the past.They won't let you down.Any word on the total quote for both ends?

author: Kjelt
author_rank: Super Contributor
timestamp: February 06, 2015, 08:33:41 am
content: Good that you found them. Another thing to consider, are both devices going to be on the same (inhouse/incompany) network or are you planning to use them on remote sites so you need to communicate over 3rd party networks eg the www.In the latter case there could be some pittfalls waiting (firewalls, port-routersettings etc.).

author: David_AVD
author_rank: Super Contributor
timestamp: February 06, 2015, 01:22:52 pm
content: The job being quoted is somewhere with an IT department that will organise the routing. The www is not part of the route.

author: Rasz
author_rank: Super Contributor
timestamp: February 06, 2015, 06:27:11 pm
content: Quote from: David_AVD on February 06, 2015, 12:54:09 amNo, this isexactlywhat you are looking for. In fact this is what you settled on, minus din rail enclosures.$25 400MHz linux box with 6-11 GPIO lines accessible from command line/bash scripts/python program/cgi/whatever you want

author: David_AVD
author_rank: Super Contributor
timestamp: February 06, 2015, 09:44:22 pm
content: Quote from: Rasz on February 06, 2015, 06:27:11 pmSo to configure it you have to fudge around with scripts, etc? No thanks.

author: Kjelt
author_rank: Super Contributor
timestamp: February 06, 2015, 09:45:36 pm
content: Quote from: Rasz on February 06, 2015, 06:27:11 pmHe only wants a single HARDWARE button in another location connected to the network.

author: Rasz
author_rank: Super Contributor
timestamp: February 06, 2015, 11:02:00 pm
content: Quote from: David_AVD on February 06, 2015, 09:44:22 pmwhat exactly is your job then? sounds like you want to charge your client for .. buying something online?yes, two $25 boxes require you to sit on your ass for few hours and write some code. Those 2x $200 boxes you found also need programming - you said you dont want to control from the web, and that means scripting two of them together.

author: donmr
author_rank: Regular Contributor
timestamp: February 06, 2015, 11:09:02 pm
content: Quote from: David_AVD on February 06, 2015, 07:43:03 amThese seem to be made byControl by Web. They have a variety of products. (I've been looking for something like this too.)

author: David_AVD
author_rank: Super Contributor
timestamp: February 06, 2015, 11:15:57 pm
content: Quote from: Rasz on February 06, 2015, 11:02:00 pmYes! You got it in one. That's how the real world works. You provide the client with a working, reliable and supportable solution. No need to reinvent the wheel every day.

author: David_AVD
author_rank: Super Contributor
timestamp: February 06, 2015, 11:17:28 pm
content: Quote from: donmr on February 06, 2015, 11:09:02 pmYeah, some cool stuff there. I can see me using this sort of gear more often in the future.