adccommunitymod (AutomationDirect) asked a question.
Created Date: February 27,2012
Created By: AlbertL
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Hello all, I'm brand new to PLCs (in fact I don't work in the controls field at all), but I somehow find myself developing one of those oddball applications that the Click PLC seems to attract. Background: GE introduced its low-voltage remote-control relay system in the 1950s as an alternative to conventional line-voltage switch wiring, mainly for lighting. Amazingly, the basic system is still around; in fact it became the foundation of GE's present automated lighting-control system, and at least two competitors make compatible relays and use them their in their own lighting control products. The GE system was originally aimed at homes as well as commercial/industrial/institutional buildings. Check out this cool two-page ad, showing the system's HMI: http://www.flickr.com/photos/atomicpear/5484215744/ http://www.flickr.com/photos/atomicpear/5484217140/ Today it's no longer marketed for residential applications, but some of those systems are still in operation, often lovingly maintained by the homeowners themselves due to a lack of electricians willing or able to work on them. There's even a Yahoo group devoted to the system: http://groups.yahoo.com/group/gelv/ . (Unfortunately, some of the residential installations suffer from what we might delicately term "wire management issues ": http://www.flickr.com/photos/atomicpear/3726445825/ ) The heart of the system is a mechanically-held SPST latching relay with 24-volt ON and OFF coils and optional pilot contacts. A momentary pulse on a coil latches the relay in the corresponding condition until the opposite coil is pulsed. The relay mounts in a 1/2 " knockout, with the line-voltage terminals on one side and the low-voltage (Class 2) control wiring on the other. Multiple relays can be installed in a central cabinet, or individual relays can be mounted in junction boxes at or near the loads being controlled. The relays are described on p. 6 of this GE brochure: http://www.gelighting.com/na/business_lighting/products/lighting_controls/pdfs/tlclvrc.pdf The Project: Anyway, I 've always been fascinated by the GE system, and have been planning a modest installation here in my small house. The functions I initially want to implement are: (1) allowing use of SPST maintained-contact devices (e.g. photocontrols or regular toggle switches) in place of the SPDT momentary-contact switches which are the system's standard manual control device; (2) providing timer control of individual circuits, with manual override; and (3) allowing control of circuits in groups (e.g. "all outside lights "), with manual override of individual circuits. I had initially looked at doing everything with discrete relays, but once I discovered the Click, a PLC-based system became the obvious choice both for economics and easy of maintenance. Although this is probably a very simple project compared with most PLC applications, there are some subtleties which make it interesting. Whether the whole project makes sense economically is a slightly different question :). But (1) I'm learning about PLCs, and (2) it's fun, and (3) it really will be useful.
Created Date: May 05,2012
Created by: AlbertL
So far, the project is going very well. This is my first experience with PLCs and it's still a learning activity, but it's moving toward the goal of becoming a practical system. As I continue with the software development, I'm also working on packaging the hardware into a code-compliant, installable form.
One issue I haven't decided is the most cost-effective way to drive the GE relays from the PLC. As noted in the previous post, the relays are mechanically-held latching relays with split coils. The most straightforward design would use two PLC output contacts for each relay: one for the ON coil and and one for the OFF coil. But an alternate wiring arrangement using diodes would reduce the PLC output requirement to one point per relay, plus two common or "master " points; e.g. a system with 10 relays would require 12 PLC outputs, versus 20 under the simpler design.
The choice isn't simple. The "diode " system not only reduces the number of PLC outputs used, but also the number of wires needed between the PLC and the remotely-mounted relay boxes. On the other hand, to make the system maintainable, I'd want to install the diodes in an orderly way - probably on terminal blocks rather than just splicing them into the relay leads. That adds to the cost, not just for the terminal blocks, but also for the cabinet space to mount them.
Anyway, that decision can be deferred; the impact on the PLC software is fairly minor.
Created Date: January 14,2014
Created by: charliehill
The Way how to control your house electronics from Internet? And not at home with you
You need to try smart plug wifi , and download APP into your smart phone and run it, than it's easy to control it any where and any time you want
:)
Created Date: January 26,2014
Created by: charliehill
Smart home switch outlet
Smart home and home automation become a heat topic more recently all around the world even in developing countries like China, as a solution for energy saving and easy-controlling by connecting with smart phone, young people also regard it as kind of fashion.
Created Date: January 26,2014
Created by: AlbertL
Yes, in fact right now I'm remotely monitoring my home's temperature through RTD sensors connected to a Click analog input module. I access the data via a web page on an Apache server. The server talks to the Click over my home LAN via an Ethernet-Modbus RTU gateway. The web page uses AJAX to continuously update the readings. On the server, an object-oriented PHP application, acting as a Modbus master, does the main work of translating Click addresses (e.g. "DF1 ") to Modbus addresses, issuing the Modbus commands, and sending the responses to the web page. The same application can also write to Click addresses, so I can control things as well as monitor them.
Created Date: January 31,2014
Created by: deep6ixed
Good Gravy... That wiring mess... I 've got entire welding machines with less wiring than that.
With PHPModbus and a webserver, you can work wonders now. A good place to start is the Do-more designer and it's built in simulator. It does network modbus with an actual plc, and that what I'm using to learn simple SCADA.
Created Date: February 02,2014
Created by: charliehill
Wifi Power socket
Wifi power socket realize remote control of home electronic appliance, it’s also a kind of fashion among young people. Wherever they are, they switch on/off their air conditioner, curtain, TV with smart phone to show they are fashion keeping.
Created Date: February 02,2014
Created by: AlbertL
You need to try smart plug wifi , and download APP into your smart phone and run it, than it's easy to control it any where and any time you want
:)
Thanks, Charlie. I like the Smart Plug concept!
Created Date: February 02,2014
Created by: AlbertL
Wifi power socket realize remote control of home electronic appliance, it’s also a kind of fashion among young people. Wherever they are, they switch on/off their air conditioner, curtain, TV with smart phone to show they are fashion keeping.
Yes, at some point I want to get into developing a smart phone app for the system. For now, I'm using a Kindle Fire's built-in web browser as a touch-screen control panel. Not industrial-grade, obviously, but cheap. I expected I'd find some critical limitations in the browser, but so far it's run all the HTML and Javascript I 've sent it.
Created Date: February 08,2014
Created by: AlbertL
Good Gravy... That wiring mess... I 've got entire welding machines with less wiring than that.
With PHPModbus and a webserver, you can work wonders now. A good place to start is the Do-more designer and it's built in simulator. It does network modbus with an actual plc, and that what I'm using to learn simple SCADA.
Yes, PHPModbus ( http://code.google.com/p/phpmodbus/ ) is a great building block - very easy to use. I wrapped it into an object which provides functions related to the Click, used like this:
$plc = new ClickPLC( IP_address );
.
.
.
$clickAddressContent = $plc->readFromClickAddress( click_Address );
$nicknameContent = $plc->readFromNickname( nickname );
$modbusAddressContent = $plc->readFromModbusAddress( Modbus_address );
If you 're working in a Windows environment, another excellent tool is Wampserver ( http://www.wampserver.com/en/ ), which provides an Apache server, PHP and MySQL in one easy-to-install package. I like developing software, but don't enjoy having to set up my programming environment - I just want to write the code and run it. Wampserver reduces the configuration work to an absolute minimum, but still gives you the ability to customize whatever you want.
Created Date: February 13,2014
Created by: charliehill
Energy saving Smart home outlet switch
Energy saving is a hot topic among all people, smart outlet switch has not only this function but also brings more conveniences to modern life, that’s why young people became crazy about this great invention.:)