PLC Control for small lab setup automation help

[cames]

Hey guys
I have a small l plc automation project im working on (side note* im a mech eng so i know very little about this stuff).

I have a small lab setup with 9 supply lines of inert gases are controlled by manual on/off valves. I want to automate the opening/closing of the valves. there's 9 manual valves currently. See attached picture of the setup and a PID which shows the valves i'm trying to control open/close.

Depending on the experiment, the opening/ closing time of each valve can vary. For example, for 1 experiment valve 1 can open 10 seconds then close, then valve 2 open 10 min then close, then valve 1 opens 20 minutes the close. Open time can vary from 20 seconds to 10 hrs.

Because the open times can vary, i don't think I'm able to use a relay timer to control the valves since 1 valve can have different open times in 1 experiment.

I had an Automation Company quote this work for me and it was quoted for around $20k for the engineering, control panel and HMI, which is absurd. I just need something quick,fast and dirty. This isnt for industrial control, just small scale bench lab work.

For the valves, i was planning on using just electric - power to open- solenoid valves.

I feel like there must be some other way to do this much cheaper since its just making a recipe for controlling the opening/closing of the valves. I have no background in this kind of stuff so i don't know what's out there. I wouldn't need a touchscreen HMI, even a computer monitor screen/mouse for display would be more than enough. I just need a way to create a recipe that would create output voltage to open/close the solenoids. It basically just 9 outputs based on a preset timer sequences.

Do any of you guys know a simple way i can do something like this, something quick and fast? i feel like there must be a simple way to do this, like a microcontroller like Arduino?
Thank you guys!

 

[Heaviside1925]

OP,
$20k for what you're wanting sounds about right if not a little low because an automation company is going to give you professional service and it sounds like you want a down and dirty back yard special.

Now as far as what will work for the cheapest. You mention solenoids for on/off control which should work. Based on what you are describing, I think that logic could easily be achieved with relays, switches and adjustable timing relays.

If you really want a PLC, I would go with a micro plc. I know both Allen Bradley and Square D make one and they have an interface that you can directly enter your logic, so no HMI or computer needed. If you know nothing about PLCs and ladder logic, this would be a great way to learn basis ladder logic control. There are a ton of YouTube tutorials you could watch. If you have decent aptitude, a couple hours of videos and practice won't make you an expert but will give you enough knowledge to do what you want.

If you really want a professional looking set up (PLC, control panel, HMI) all meeting local and national codes, then you are either going to need to train yourself in all of these subjects or hire and automation company. There really no easy way around this one.

 

[Heaviside1925]

OP,
I just noticed something in your original post.
Do you know how to program an Arduino? If so, you need I/O cards for discrete signals and you can do all your programing through logic statements. You can also interface with any HMI you wish.

 

[tygerdawg]

Seems on the surface a very simple project requirement. Heavi is realistic on costs...if you contracted it out. The contractor has liability, insurance, salary, and overhead expenses that must be paid. Your company may force you to have it done professionally by third parties.

If you don't need a commercial-level solution, then I think this would easily be a roll-your-own affair. First thoughts would be a simple inexpensive brick-style PLC from Automation Direct (or others, but I like AD). I would go ahead and add their inexpensive touch screen HMI for program selection and execution convenience. Let the PLC control a bank of solenoid valves for gas flow. ASSUMING the gas is not corrosive etc and incompatible with the SVs.

The solenoids would be inductive loads on the I/O, so it would have to be determined if the I/O circuitry would survive such loads. If not, then might need to upgrade to a PLC with stackable I/O and add a relay output module or two.

Maybe you live near an Engineering Uni or a Technical College. You may consider contacting the appropriate Department for some consulting / programming time. It would make a great student learning project. Else, this would be a wonderful opportunity for you to add to your skill set with this simple project.

TygerDawg
Blue Technik LLC
Manufacturing Engineering Consulting

http://www.bluetechnik.com

 

[Heaviside1925]

tygerdawg This is great! roll-your-own affair if not copyrighted, trademarked or otherwise protected, I would like to request you permission to add this to my rolodex for future appropriate use.

 

[3DDave]

"I just need something quick, fast and dirty."

That's also known as a lab assistant, though automation doesn't ruin a run with a bathroom break.

Also, part of the reason for the high quote is that every temporary solution that works can easily become a permanent solution, so they are specifying components for a 20 year life.