PLC Advice - Home Automation Needs

Join Date
Jul 2015
Location
Somewhere
Posts
6
Hi All,

I have been searching through post to post trying to find answers to some questions I have. But somehow I believe I am going round in circles now and hence would need your help.

My Need:
I am building a new house and before the wiring commences I am trying to get the logistics in place.

Approach:
1. I want to control lights, fan & other electrical equipment within the house using a PLC connected to the mains.
2. There will be no inputs connected to the PLC rather the plan is to add small wireless sensors throughout the house which will send a command (presence detection) to the server.
3. The server will then send a command to the PLC or Raspberry Pi connected to the PLC to switch an output port On or Off. (I have seen parts of this working on many youtube videos)
4. Post the timeout the server will send an Off command to the specific port of the PLC
5. I will be using python as the main coding language wherever possible.

My Reasoning:
1. I am not building any logic inside the PLC rather using it as an alternative to Cheap Chinese Relay Boards that I am getting in my country OR probably I do not know how to select good quality wifi/ethernet enabled Relay Boards. Either ways PLC is my first preference.
2. I am already getting a server room with 2-3 units so it makes a lot of sense allowing the server to control the PLC which allows me a lot of flexibility to modify timeouts, logic sequences etc. on the server itself using a UI.

Background:
1. I am new to the PLC World - less than 2-3 weeks of theoretical experience (neither do I own a PLC and neither do I know anything about PLC programming - AS OF NOW)
2. I am looking at either Delta or Omron PLC's - ES2/EX2 or CP1E to help me do this. I am more inclined towards Omron CP1E-N30DR-A for my needs and I want to add a couple of Output only ports to it.
3. WAGO - A lot of information is available for these on the net and on youtube but unfortunately they are only modular. I spoke with their representative in India and am waiting to hear back from him on a possible configuration for my needs and to check if it fits my budget. The Omron's or Delta's do fit.

My Questions:
1. Would my choice of PLC's do the task of switching on or off lights, fan etc properly ?
2. How will output power be supplied to these units - lights, fans etc. ? Do I have to go after a specific voltage based PLC or buy a power module separately ?
3. Would using an Ethernet module with the PLC rather than Pi provide more stability and reduced latency ? If yes what is the communication medium I will have to study about ?
4. Would using a modular PLC be advisable or I can go with the chosen options ?
5. Can someone please direct me to a website / book / article / video anything which can help me learn about these:
-- Basic Programing knowledge which will be required in my case
-- Setting up a PLC
-- Communicating using Ethernet or advisable communication ports
6. Digital or Analog output which one should I prefer ? I want a dim effect on all my house light when they are switched on or off. i.e. they should create that soft on or off feel.

I know many might advice me to go and get some professional help or get an existing automation solutions like Insteon or Zigbee etc... But I like challenges and coming from a commerce background I could program, manage a server room, design a wifi motion sensor etc. etc. SO I hope you get the gist... if you could guide me I will be thankful... Anyways thanks a ton for stopping by.. I appreciate it :)

Regards
OFD
 
1 - The PLC outputs do not usually switch the load directly. They are usually rated around 2Amps maximum. Usually an interposing relay or solid state device is used to handle the switching.
2 - You would supply the power to the unit through the output. See manual for the PLC you decide to use.
3 - I would go with the Ethernet module. The Modbus TCP protocol will work.
4 - This is just a mater of choice. Check the specifics of the installation in relation to the loads to determine if other options are better. I would check out the following PLC:
Automation Direct Do-More
5 - http://accautomation.ca/now-you-can-have-robust-data-logging-for-free-part-1/
Logging tutorial on Modbus TCP using VB
6. If it is just lights that you are dimming then using multiple outputs for switching might be a more cost effective solution to change the voltage to the lamp.

These are just my thoughts.
Hope they help you out,
Regards,
Garry
http://www.accautomation.ca
 
6. Would modern LED lights be dim-able with PWM? If so choose SS-relay and an PLC or interface that does PWM. (click)

You could do the entire thing with the raspberry PI. I run codesys on mine and use arduino connected wirelessly. Protocol I am using with that is a version of modbus that I changed slightly (click)

Depending on how many arduino's you would need that could be a cheap choice.

Anyway, welcome to the forum, and keep us updated!
 
I think this is a super cool idea and I am not trying to deter you from doing an automated house BUT, what if you are ever to try and sell this house. A non tech savvy purchaser may not even consider such a purchase.
Will there be some type of manual control for when the blackberry kicks the bucket?
You would have to offer a support contract !
Just kidding.
 
I don't think the CP1E-N30DR-A has any Ethernet capability unless you add the option board for it, adding cost as well. Since you aren't going to use the PLC for logic programming, it seems like a lot of added cost for no real benefit.
 
I don't think the CP1E-N30DR-A has any Ethernet capability unless you add the option board for it, adding cost as well. Since you aren't going to use the PLC for logic programming, it seems like a lot of added cost for no real benefit.

That's absolutely right... I am also looking at the add on ethernet card... and I agree thats a lot of cost.. but somehow with my budget of around $1500 for approx 100 output ports / relays switches I am includes towards this. DO you have any other option in mind ?
 
I think this is a super cool idea and I am not trying to deter you from doing an automated house BUT, what if you are ever to try and sell this house. A non tech savvy purchaser may not even consider such a purchase.
Will there be some type of manual control for when the blackberry kicks the bucket?
You would have to offer a support contract !
Just kidding.

Good point.. its an ancestral house and we have it from the past 40+ years.. will have it for another 40+ if things remain okay :)

Yes, I am planning for a manual override switch for each socket.. not sure how.. but luckily I have my local WAGO guys showing a lot of interest in this project.. They are coming over tomorrow.. lets see how it goes :)
 
1 - The PLC outputs do not usually switch the load directly. They are usually rated around 2Amps maximum. Usually an interposing relay or solid state device is used to handle the switching.
2 - You would supply the power to the unit through the output. See manual for the PLC you decide to use.
3 - I would go with the Ethernet module. The Modbus TCP protocol will work.
4 - This is just a mater of choice. Check the specifics of the installation in relation to the loads to determine if other options are better. I would check out the following PLC:
Automation Direct Do-More
5 - http://accautomation.ca/now-you-can-have-robust-data-logging-for-free-part-1/
Logging tutorial on Modbus TCP using VB
6. If it is just lights that you are dimming then using multiple outputs for switching might be a more cost effective solution to change the voltage to the lamp.

These are just my thoughts.
Hope they help you out,
Regards,
Garry
http://www.accautomation.ca

Thanks for your advice, I appreciate it.. Unfortunately I do not get Automation Direct products in India.

Any others that you might recommend which would serve my purpose ? I do get Omron, Delta, WAGO, Micrologix and the other big brands (ABB, Schneider, Siemens etc).

Also, any starting point where I can get some practical advice regarding shortfall of using a PLC vs Relay for my purpose ?
 
6. Would modern LED lights be dim-able with PWM? If so choose SS-relay and an PLC or interface that does PWM. (click)

You could do the entire thing with the raspberry PI. I run codesys on mine and use arduino connected wirelessly. Protocol I am using with that is a version of modbus that I changed slightly (click)

Depending on how many arduino's you would need that could be a cheap choice.

Anyway, welcome to the forum, and keep us updated!

Thanks for your advice.. appreciate it.

For my use.. automating nearly 100 light switches across 5 floors.. PLC or Combined Relay Boards would be a cheaper option... that is again in my noob opinion.
 
Look into current home automation system. Zigbee and Zwave are both popular systems and are mesh networks so commands relay across the network back to the controller. You can buy switches, outlets, sensors for Lumens, humidity, magnetic(door/window status), etc.


Various controllers exist that are either buy or free. Free you can get Home Assistant, it has a mirade of addins that are also generally free. One very nice addin for it is Node Red, its a sort of flow based logic programming system. If you've every programmed DeltaV is looks similar in how things link together and flow. You can buy Hubitat, Domesticz, HomeSeer (can run on windows or a RPi.

You can use a PLC ( I was curious and looked into it..) but the costs won't balance out with a Home Automation system.

Plus HA switches are still locally controllable even if the system goes down, just lose the smarts.
 
Sorry if I sound negative, it's not my intention. But are you absolutely sure (as far as possible) that you will not sell this house at any point in your life? Because all of these things will have a negative impact on the price that you may sell it for. Also, before you do a lot of it, think whether you want to arrive home and troubleshoot why the lights aren't working with your wife overlooking.

As for technical solutions, since you don't care for a PLC and seem to have more experience in the Computer side of things, why not just buy remote IO modules and read values off of them?

You can get IO modules that talk Modbus and plenty of ready to use protocol implementations off the internet. I'd risk that some of the larger brands probably have something that you can read data off of, but have never looked into it so can't quite say.

You should take into account the total price too. A lot of people think the main cost is the PLC or IO and, although it's the larger chunk, the instrumentation or actuators that work off of 24V or 4-20mA are quite expensive for what they are and an easy thing to overlook on the price.

I don't know your background or why you must use PLCs for this, but if smaller electronics interests you, you can look at Arduinos or similar to get sensor readings and so on. It's more work, but can be a lot cheaper for things like sensors. I wouldn't say that's the same for actuators as it requires more engineering on the power side so something out of a box should work best.

Lastly, run conduits before the house is finished. This will also depend on the method of construction, in the UK you can run stuff inside walls fairly easily. In many places in continental Europe that's not the case and you have to break through brick to run anything on a wall. Also, conduits will let you spread the cost over x amount of years.

P.S.: Do take in consideration energy efficiency and metering.
 
I guess the house is either ready or the project is cancelled after 5 years. The last activity is in July 2015, until the Miracle of Resurrection Of Old Topics happened yesterday.
 

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