New to PLC - Need advise for current project

[lasersailor]

I know virtually nothing about PLC. Some VBA experience. My project, using a simple analogy, is to make a programmable door bell ringer. I want to be able to create the ringing pattern in a PC program and download it to a PLC that will control a solenoid that will ring the bell. The functions that need to be controlled are: 1) create a variety of ringing patterns (musical score - only one note), 2) pick the score to play, 3) set the duration of the score 4) set a timer to determine a schedule for the program (this could be very simple in the beginning, just certain hours of the day. Later it could be programmed picking days and time frames in the future). The controller should have an attractive but simple user interface. After creating all the functions, turning the bell on and off, picking the musical score and the schedule should be done from the controller on the bell.
I want to know if this can be done with an existing controller (or if I need to have one made), how to pick that controller and some help with the PLC programming. Cost of the controller is a concern. I don't have time to learn everything to complete this project so want help. Looking for someone that might have an interest in helping me with this as a practice exercise, or just for fun.
Thanks,
Greg

 

[JeffKiper]

Greg this ound like homework am I right?
how are we to know what processor you have I didn't see any specs on the current system. We need to see what you have started with before we can offer any help.

 

[bernie_carlton]

We had a few AutomationDirect DL06s about, most with defective outputs (our fault).

The 'powers-that-be' asked me to set up start of day, break, lunch and end of day bells controlled by the PLCs.

But I couldn't just do an ordinary job.

I let them set up the pulsing pattern of a specific bell (and name it), attach a specific time of day, save the total day's pattern and name that days setup, and finally assign a given day type to each day of the week.

The set up is by a Visual Basic program which the supervisor has on his desktop.

We have a few different buildings so I allowed different setups (each in its own DL06) to be done for each if they go on different schedules.

They seemed to have fun with it and the bell patterns are very distinctive.

 

[lasersailor]

Jeff,
No, this is not homework in the sense that I am taking a class. This is just a personal project I have wanted to do for a long time. I want to do the programming on a PC and then move the program to a PLC. I have not selected any equipment (Processor) yet. That is part of my question. I really don't know where to start and that is why I am posting here. Starting with a general description of what I need and the steps I should take would be helpful.
Thanks,

 

[lasersailor]

Bernie,
This sounds very similar to what I want to do. I looked up a AutomationDirect DL06 and it looks like serious overkill for what I want to do. I only need to control one solenoid. It is helpful to know that you did the PC programming in VB. Other than that, does my concept of letting the user program the pulsing pattern on a PC and downloading the program to the PLC via a USB cable sound right. Sorry, but I really have not electronic or PLC experience so my questions are very basic to start.

 

[bernie_carlton]

Actually the PLC itself (using a program written using software specific to the PLC) is doing all the comparisons to its internal Real Time Clock and activating the output.

What I wrote In VB was an operator interface allowing the supervisor the ability to modify tables within the PLC to affect the sounding of the bells and the timings.

So, if you use a PLC, you won't write the program for it in VB or do any active real-time control. But you can make a very nice interface. All you need is the specific PC to PLC communication package.

 

[bernie_carlton]

A really inexpensive item to try is the Click PLC by AutomationDirect. It needs 24VDC. But the software for it is free.

Otherwise, learn about the basics of PLC control with Phil's online course (see 'Learn PLCs' at the top of this page).

 

[milldrone]

Bernie,
This sounds very similar to what I want to do. I looked up a AutomationDirect DL06 and it looks like serious overkill for what I want to do.

I believe there were two reasons for the "overkill"

1. They were just laying around (crippled).

just certain hours of the day. Later it could be programmed picking days and time frames in the future).

2. The DL06 has a real "time clock" (needed for the time of day thing). Not all low end PLC's have the real time clock.


The analog version of the CLICK PLC from Automation Direct also has a real time clock and the software is free.

Edit: I see Bernie already mentioned the click.

 

[lasersailor]

Vaughn,
Yeah, I get the just laying around part, but the real time clock is interesting new information. My original "overkill" reaction was that the DL06 looked like it would cost a lot more than I imagine I would need to spend to get the job done. I have had a suggestion that a MCU is more appropriate for my project because there could be problems with the PC communication and the MCU is faster and more flexible. Do you know if MCU's can have the real time clock function. Do you have any thoughts on the MCU vs PLC decision relative to my project. My project seems so simple that a pretty simple controller should do the trick (from a perspective of not knowing quack about any of this).

 

[Ron Beaufort]

just something to think about ...

if the reason for doing this project in the first place is to LEARN about PLCs, then consider that paying just a LITTLE BIT more (but not a LOT more) might turn out to be a wise investment in the long run ...

when you get "finished" with this project, you'll probably want to add more "bells and whistles" to it - or maybe tackle something else a little bit "meatier" ... having a little bit of extra horsepower under the hood might be well worth the few extra bucks it will cost you up front ...

survival tip: if you're married, don't let your wife know how much you enjoy this stuff ... once that happens the little darlings tend to regard every purchase as "more toys" - rather than an "investment" in the future ...

and welcome to the forum ...

 

[lasersailor]

Ron,
To be honest, I would love to have the time to learn all about PLC's. It think it would be great fun. However, I am still struggling with learning curves in MS Access, Dreamweaver, .net PHP and other assorted stuff that actually relate to me making a living. I really just want to get help on this project and learn what I can along the way.

I have to confess I don't have a clue about what you mean by paying a little bit more to get extra horse power under the hood. Does this mean equipment that is required to complete my project. I am so new to this I don't even understand what the steps are and the equipment required to do my project and no one that has responded has shed any real light on that (although I have located suppliers for solenoids). A broad overview would be tremendously helpful.
Best Regards,
Greg

 

[leitmotif]

What Ron is telling you is to buy extra capacity up front. When you complete the doorbell you will then think of the next project. If you bought unit with extra inputs and output you will already have a PLC ready to go and able to handle it.

Dan Bentler

 

[Ron Beaufort]

here's one handy resource ...

have a look around at the following site ...

http://www.plctrainer.net/

the owner is one of our valued forum members who should be able to help you decide what you need ...