HI! every1 thanks in advance!!

Im looking to program a PLC to be operated by swipe cards with a database and daily limits can anyone help me do this? It seems to me to be easy to do but I need to know where to start can some one help me please? Thank - you ! Your assistance is appreciated more than you will ever know, Thanks, Bill

What kind of data are you reading from the cards? What do you need to do with it? Why do you think this is a good application for a PLC? What brand and model PLC do you want to work with?

People have been interfacing bar code readers with PLCs for years. I can't imagine a swipe card being significantly different.

Hi Steve, Thanks, the data I am reading is customer ID's and I want to assign a limited number of swipes per day. Why a PLC ? I'm told they are bullet-proof . the application is for a self service car wash pre - paid customer card. the out put from the PLC could be converted by relay to my timer (pulses) What brand ? what model ? Dunno. I'm open to suggestions there as well. Thanks - Bill

Are you hooked on swipe cards? Is there a PLC currently controlling the car wash or is your system simply going to open the door?

Since this is a relatively low margin business I would be more inclined to issue the customer a random number when purchasing the set number of washes and then place a keypad outside the car wash whereby the customer would input their "code" in order to open the door. This is how every automated car wash I have ever been through works. Do you really want to have someone throw away their card if they only bought one wash.

A little more detail and we can help better.

Sure allscott , More details - I want to sell 1 year all you can wash cards with a limited amount of swipes per day I.E. 5 swipes each swipe would be converted to a pulse or pulses read by my timer , and the PLC would database and limit the amount of allowed swipes per day and reset at midnight. And allow the process again for the next day.each card would have its own ID. As to your other question of what PLC do I have - I dont. I am at theory stage of this operation like I said All the help I can get is usful . Thanks, Bill

The problem I have with a PLC for this application is the limited amount of data storage available, especially in the low-end models, which is all you really need based on the amount of I/O and the lack of complexity.

How much research have you done into the capabilities of card reader systems? I don't know a thing about them myself.

I'm thinking that a simple viable system would be something that can both read from and write to the card, like an RFID system. The card data would need to include something that identifies it as one of your cards, an expiration date, the last date/time it was swiped, and a number between zero and five.

Each time the customer swipes it, the system checks for validity and the "swipes remaining value greater than zero, then checks the date/time of the last swipe. If the last time was today, deduct one from "swipes remaining" and write back the current date/time and the new "swipes remaining" value. If the last swipe was not today, write back the current date/time and "swipes remaining" equal to four. You might not even need a PLC.

Could work

Do you really need to track all the customers? How many customers in 24 hours? That is the magic number. Then just run a loop and look for this customer ID and count how many times the ID shows up. This would be simpler than having a Database of customers tracking all washes.

How long is each wash?

24hrs/wash time = max washes per day
max washes per day = max size of lookup table

You may want to check this out. I have used some of the bar code readers but I don't know much about the mag stripe readers.

http://www.waspbarcode.com/point_of_sale/magnetic_stripe_reader.asp

HI, Charles I'm not married to mag cards a bar code card could work .That was my working theory .If you use a plc for this APP what one would you use? Thanks, Bill

I was considering a rfd or a smart card i just needed some software scheme your getting close to what I need. Thanks again ,Bill

I used to work for a mfg company that used swipe cards for varying access levels to its most high tech assembly machine. They were quite reliable and very handy. The card reader was connected to a PC through a serial port. That could have just as easily been a PLC serial port. The users each had a unique ID that was associated with all setup value changes. In this way, each person could be given different access based on his/her level of training and capability, and everyone knew their actions were logged. All in all it was a very functional system. I was not directly responsible for the machines so I don't recall the hardware details.

I do know that the readers and cards were much more rugged than barcode readers. These guys used to just toss their cards in their toolboxes. They would work until they were severely scratched or cracked, and making a new card was very cheap and easy too. The readers were much less expensive than laser barcode scanners in my experience too.

In my opinion, the whole concept is a great idea and I think the mag card reader might be the best method to handle it.

I also concur with CharlesM on the PLC keeping up with 24 hours worth of customer data. You could easily add a PC to record that information for your annual totals. Like you said, the PLC is more bulletproof that a PC, so you really don't want to totally depend on a PC to keep your busine$$ up and running.

I don't have any experience with RFID, but will be involved in a project next year. It looks very promising for your application too, but may be quite a bit more expensive to implement.
Paul

I seem to be convinced that a PLC is the way to go can anyone give me a make or model of PLC that would do what I want to do? Thanks Bill .

Bill,

We have actually done this for a customer that does coinless laundry facilities. Through the operator interface, this application can store up to 500 cards, with various refresh code levels.

Here is the article we posted - http://www.entertron.com/einl/app4.htm

If this is what you are looking for, feel free to contact us.

Hope this helps.

God Bless,

Hi Steven Thanks! i certainly will get back to you this may just be the answer to my prayers! Thanks again everybody ! and any other input is still very much appreciated. Thanks!