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Anyone with plc experience?

Started by default August 13, 2019
I was looking for a ready made timer for a hydroponic system I'm
tinkering with and came across some el-cheapo PLCs on Amazon, and
figured this would work lots better than a timer that would need a lot
of additional circuitry to adapt.

The catch is that they mention a programming software that is from
Mitsubishi and costs $500+ .  After looking around I found some
cheaper alternatives but with more expensive hardware,  Further
searching led to an open-source software, but I'm ignorant of all the
standards and protocols they are mentioning.

Is there a newbie group for this sort of thing?  I see a lot of "home
automation," but they want cell-phone control plug-in stuff and it is
still costly.

I'm used to BASIC software for control applications, and most of the
PLCs use relay logic and I've used the "Automate" PLC in the 70's when
they were huge beasts - but easy to program with relay logic.  For the
hydro, I only need relay or OC outputs and switch inputs, nothing
fancy.  Initially I'm only controlling lights, hi/lo temperature
switch, hi/low nutrient switches, and switching a pump on and off.
In article <m775letps0i2920b4i80pfa9qd2jblcr2o@4ax.com>, 
default@defaulter.net says...
> > I was looking for a ready made timer for a hydroponic system I'm > tinkering with and came across some el-cheapo PLCs on Amazon, and > figured this would work lots better than a timer that would need a lot > of additional circuitry to adapt. > > The catch is that they mention a programming software that is from > Mitsubishi and costs $500+ . After looking around I found some > cheaper alternatives but with more expensive hardware, Further > searching led to an open-source software, but I'm ignorant of all the > standards and protocols they are mentioning. > > Is there a newbie group for this sort of thing? I see a lot of "home > automation," but they want cell-phone control plug-in stuff and it is > still costly. > > I'm used to BASIC software for control applications, and most of the > PLCs use relay logic and I've used the "Automate" PLC in the 70's when > they were huge beasts - but easy to program with relay logic. For the > hydro, I only need relay or OC outputs and switch inputs, nothing > fancy. Initially I'm only controlling lights, hi/lo temperature > switch, hi/low nutrient switches, and switching a pump on and off. > >
You may want to check out the Arduino. You can get the basic modules from ebay for around $5 and some relay boards and many other things very cheep. Usually from $ 5 to $ 20. There is some programming software that is free to download off the internet. They program up using what seems to be C++ or similar language. The boards remind me of a PLC as they have about 10 outputs of 0 or 5 volts and a few other outputs and about the same ammount of input pins. There is a book "Getting Started with Arduino" by Banzi and Shiloh that goes through the programming and shows how to build an program a system to automatically water your garden. You can go here to learn about them. https://www.arduino.cc/ On the internet and youtube there are thousands of programs (which are called sketch).
Automation Direct sells 69 dollar PLCs and  their software is free.
Eric
On Tue, 13 Aug 2019 10:48:58 -0400, Ralph Mowery
<rmowery28146@earthlink.net> wrote:

>In article <m775letps0i2920b4i80pfa9qd2jblcr2o@4ax.com>, >default@defaulter.net says... >> >> I was looking for a ready made timer for a hydroponic system I'm >> tinkering with and came across some el-cheapo PLCs on Amazon, and >> figured this would work lots better than a timer that would need a lot >> of additional circuitry to adapt. >> >> The catch is that they mention a programming software that is from >> Mitsubishi and costs $500+ . After looking around I found some >> cheaper alternatives but with more expensive hardware, Further >> searching led to an open-source software, but I'm ignorant of all the >> standards and protocols they are mentioning. >> >> Is there a newbie group for this sort of thing? I see a lot of "home >> automation," but they want cell-phone control plug-in stuff and it is >> still costly. >> >> I'm used to BASIC software for control applications, and most of the >> PLCs use relay logic and I've used the "Automate" PLC in the 70's when >> they were huge beasts - but easy to program with relay logic. For the >> hydro, I only need relay or OC outputs and switch inputs, nothing >> fancy. Initially I'm only controlling lights, hi/lo temperature >> switch, hi/low nutrient switches, and switching a pump on and off. >> >> > >You may want to check out the Arduino. You can get the basic modules >from ebay for around $5 and some relay boards and many other things very >cheep. Usually from $ 5 to $ 20. There is some programming software >that is free to download off the internet. > >They program up using what seems to be C++ or similar language. >The boards remind me of a PLC as they have about 10 outputs of 0 or 5 >volts and a few other outputs and about the same ammount of input pins. > >There is a book "Getting Started with Arduino" by Banzi and Shiloh that >goes through the programming and shows how to build an program a system >to automatically water your garden. > >You can go here to learn about them. > >https://www.arduino.cc/ > >On the internet and youtube there are thousands of programs (which are >called sketch). > >
That was Plan A - just program a pic microcontroller, and use the ready-made clock timing module to keep it accurate, but I'm intrigued by these Chinese PLCs that cost ~$15 with all relay outputs, and built for industrial control environments, and super easy to program.
On 13/8/19 13:42, default wrote:
> I was looking for a ready made timer for a hydroponic system I'm > tinkering with and came across some el-cheapo PLCs on Amazon, and > figured this would work lots better than a timer that would need a lot > of additional circuitry to adapt. > > The catch is that they mention a programming software that is from > Mitsubishi and costs $500+ . After looking around I found some > cheaper alternatives but with more expensive hardware, Further > searching led to an open-source software, but I'm ignorant of all the > standards and protocols they are mentioning. > > Is there a newbie group for this sort of thing? I see a lot of "home > automation," but they want cell-phone control plug-in stuff and it is > still costly. > > I'm used to BASIC software for control applications, and most of the > PLCs use relay logic and I've used the "Automate" PLC in the 70's when > they were huge beasts - but easy to program with relay logic. For the > hydro, I only need relay or OC outputs and switch inputs, nothing > fancy. Initially I'm only controlling lights, hi/lo temperature > switch, hi/low nutrient switches, and switching a pump on and off. >
Industrial Shields https://www.industrialshields.com/ have PLCs based on Arduino. It seems that *finally* there are alternatives to the overly expensive traditional PLCs. (I have no connection to industrialshields. I have just seen their products and liked the idea) Pere
On Mon, 9 Sep 2019 09:48:56 +0200, o pere o <me@somewhere.net> wrote:

>On 13/8/19 13:42, default wrote: >> I was looking for a ready made timer for a hydroponic system I'm >> tinkering with and came across some el-cheapo PLCs on Amazon, and >> figured this would work lots better than a timer that would need a lot >> of additional circuitry to adapt. >> >> The catch is that they mention a programming software that is from >> Mitsubishi and costs $500+ . After looking around I found some >> cheaper alternatives but with more expensive hardware, Further >> searching led to an open-source software, but I'm ignorant of all the >> standards and protocols they are mentioning. >> >> Is there a newbie group for this sort of thing? I see a lot of "home >> automation," but they want cell-phone control plug-in stuff and it is >> still costly. >> >> I'm used to BASIC software for control applications, and most of the >> PLCs use relay logic and I've used the "Automate" PLC in the 70's when >> they were huge beasts - but easy to program with relay logic. For the >> hydro, I only need relay or OC outputs and switch inputs, nothing >> fancy. Initially I'm only controlling lights, hi/lo temperature >> switch, hi/low nutrient switches, and switching a pump on and off. >> > >Industrial Shields https://www.industrialshields.com/ have PLCs based on >Arduino. It seems that *finally* there are alternatives to the overly >expensive traditional PLCs. > >(I have no connection to industrialshields. I have just seen their >products and liked the idea) > >Pere
I'm more interested in the <$20 PLCs with relay logic programming. I can program a PIC to do what I want for ~$3. But then I still need relays etc to interface it. The ones for $14-18 already have relay outputs and program with an RS232 cable. Since I have zero experience with Arduino, I want relay logic programming not another hobby...