Whats a “Windows PC” ???
apt purge $(dpkg -l | awk ‘/microsoft/{ print $2 }’) && format c: /fs:NTFS
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Unfortunately the PLC programming software for this (and most automation systems) is only available for Windows. Nothing for UNIX, Apple or Android LOL
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Well, Apple is based on BSD (Unix), Android is based on Linux, Windows stole from both and still uses BSD tcp/ip stack
I moved off of windows in the 90’s (windows 95) and moved to linux
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There is actually more automation in linux than what windows offers
Most of your tv’s, your tv setbox, refrigerator’s, cars, use linux
In 1997 the NASA (space shuttle) got rid of windows for linux in it’s “hydroponics” tests and never looked back.
https://www.debian.org/News/1997/shuttle1
Sorry, didn’t mean to start a war, but software for automation is more linux than windows
I don’t use automation, but see many companies and the public do so.
So now I will keep my 2 cents to myself and let you Rock & Roll
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Some PLC based control systems have nothing more than the PLC and the machinery just does what it is supposed to do. There are likely switches and what not that the machine operator can use to “tell the system what to do”. For example there might be a switch to start/stop the process or you might have switch that tells the system to use veg vs flowering light schedule.
Other PLC based control systems have a user interface panel (UI) or a Human/Machine Interface (HMI). The UI and HMI are two terms for the same thing. A panel with a screen (a touch screen in our case) which has various “buttons”, “indicators”, etc configured or programmed into the panel. The panel is also programmed to communicate with the PLC.
There is separate software for programming the HMI.
Yet another type of system combines the PLC and HMI into a single unit. In this case the same software is used to program both the PLC logic and the HMI.
The separate PLC and HMI allows for much more flexibility and expandability. The combined (or integrated) units are typically fixed, which means that you can’t expand the I/O (ie the number of things that you can connect to the PLC).
There is, of course, a cost trade-off.
Deciding which route to take will be covered in the course material.
For some (maybe even, most) the answer may well be to stick with timers. That is a perfectly reasonable choice.
My aim is to provide folks with the information needed to make the best decision for them.
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There is yet another class of control hardware called a “programmable relay”.
Programmable relays are not as capable as a PLC but if all you want to do is turn things on and off at certain times or when certain events happen, this might work for you.
Programmable relays can cost from around $80 to several hundred dollars. You get what you pay for in terms of features and capability.
If I were running a single 4’ X 4’ tent or closet, perhaps a programmable relay is the answer. We won’t be discussing programmable relays in detail but many of the general principles apply, just much, much simpler.
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I feel bad now, I didn’t mean to hi-jack this thread, sometimes it is best to keep things to myself, my apologize 
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No worries, you brought up an interesting point. It was valid.
I don’t think anyone feels it started any fights or anything.
I only see it allowing for some clarification about what is available for the average home consumer.
happy posting and discussing,
MacG
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In your experience do most of the appliances we want to automate require analog power switches? Or at least the ability to return to the last settings if there is a power interrupt?
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If I am understanding your question, the PLC processor module has a battery which will retain program memory for about two years (on a fresh battery). When power is lost and later restored the program will restart using the values that were in memory when power failed. The battery should be replaced annually to insure proper operation.
Examples in my program are Flower vs Veg, temperature and humidity setpoints and number of days since flipping. They would all be restored to previous values on power cycle.
There are some values that you want to start with some known value rather than the previous value, that is easily setup as well.
The processor also has a “Real Time Clock” which continues to run on battery during a power outage. The processor will have the correct time when power is restored.
If this did not answer your question, let me know so we can try again.
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My question is specifically about the appliances the controller will control. For example, a lot of dehumidifiers have digital controls, and when power is interrupted to them, they do not turn back on or, if they do turn back on, they turn back on with default settings that are different than how you want the dehumidifier to be configured. A lot of air conditioners don’t have remote thermistats, etc.
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Ah, I get the question.
That is the beauty of this sort of system. Many of the devices such as dehumidifiers and A/C units can be set to just run continuously. Setting the unit to run continuously you then use the PLC and the PLC inputs to decide when to turn power on to the specific device that you want to turn on. I selected my equipment to have a continuous mode to facilitate this sort of external control.
If the unit that you have does not have a continuous mode, it may be necessary to jumper out or bypass the internal thermostat or hygrometer to force continuous operation.
For the PLC to be able to control devices in this way, we must be able to sense temperature and humidity and get those values into the PLC for processing. In my case I use a Dwyer Instruments device which is called a temperature/humidity transmitter. This device sends a 0 - 10 volt signal to the PLC, one channel each for temperature and rHumidity. This 0 - 10 volt signal is then converted in the PLC (you must program this) to give us a temperature in F or C and relative humidity in percent (0 -100%).
The temperature/humidity transmitter cost me around $100. Barely more than a decent thermostatic switch which can only open and close at one setpoint.
We can then use these values to determine when equipment is turned on or off.
You mentioned that some devices have remote sensors, the remote sensors are not useful to us if we are using the PLC values to control the device. Having remote sensing does not cause us any difficulties so long as the device has a continuous mode.
The remote sensing input to the A/C unit or dehumidifier may be able to connect to the PLC output and control the unit in that fashion. The unit that I have does not actually turn off when the temperature is reached, it just quits cooling but the fan continues to run which use electricity with no real benefit. That is another reason why I use the PLC to control power to the A/C unit rather than use the remote sensor input.
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@bogleg, you bring up a very important point regarding devices (appliances?) that we wish to connect to our control system.
When we select equipment for a grow room which will be controlled using typical timers, we don’t really need to be concerned with “interfacing” these devices, just whether they will do the job and we can afford them.
With an integrated control system (in our case using an industrial PLC) we must select devices which will be compatible with our design and the other equipment in the system.
One example is choosing a temperature/humidity transmitter. The transmitters that I am using are capable of sending a voltage signal or a current signal to the PLC. I have them set for voltage because the input modules that I selected accept 0 - 10 volts. The “current” devices would be a more appropriate choice if we had electrical/electromagnetic noise issues to deal with. If I had not been aware, it would be very easy to select a voltage input module and a current field device (or vice versa). This would not work.
When we are connecting analog devices such as temperature or humidity transmitters to our system it is crucial that we use appropriate cable (shielded) and that the shields are properly connected to ground at only one end of each cable (PLC end) and isolated at the other. If this is gibberish to you, we will clear this up over the next few discussions.
The choice to go with industrial automation imposes a set of constraints on most of the other equipment that can use. Are these constraints reasonable for your situation? The answers will likely fall in a wide spectrum.
It is best to come up with an overall system design before locking in on a specific set of equipment choices including the choice of whether or not to use industrial automation equipment at all.
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Thanks for the info. I’m excited to learn more
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Were you able to make sense of my jibber jabber?
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I’m a Apple guy but if this will help me manage my grow and help me get a better harvest, sign me up. I’ll find a windows computer somewhere. I just need to know what version of windows and computer requirements so I can be ready. Thanks
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Any Windows 10 computer will work, likely a Windows 7 would work as well. You are on the list.
You don’t need to rush on this, at this point in time. A couple of weeks at least.
Welcome @countrybud.
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Thanks for the warm welcome.
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