Mini PLC OPC app

Good day most esteemed members, lurkers and other interested parties. I have an application where I need to monitor only 2 digital inputs and control one digital output. I need to pull this data into an OPC for use with 3rd party software. It can be a plc or non plc solution, perhaps SoftLogic or a PCI controller card, cost is an issue, I am currently using a Simatic S7-200 PLC with a Ethernet module connecting to Simatic PC Access OPC software.

Any ideas would be greatly appreciated. Like I said cost is a factor, so it does not have to be a Siemens solution.



Thank you

Run your 2 inputs and 1 output to the existing Siemens S7-200 PLC.

One of the important questions is how you need to connect it to the PC. If it's far away on a LAN or WAN network, then Ethernet and TCP/IP are probably part of the solution. If it's on the desk next to the computer, then RS232 or USB are cheap and simple.

If I were pursuing an Allen-Bradley solution, I'd get a MicroLogix 1000 10-point controller, connect it to the serial port, and use Software Toolbox, KepServer, or RSLinx Single Node as the OPC server.

A Modicon solution using the Twido mini-controller could use a Software Toolbox or KepServer or other Modbus OPC Server.

Are you building just one of these, or hundreds ? Are they going to be installed in SA or elsewhere ?
What are the voltages for the Inputs and Outputs ?

Thank you Ken, here are my responses, your input would be greatly appreciated



One of the important questions is how you need to connect it to the PC. If it's far away on a LAN or WAN network, then Ethernet and TCP/IP are probably part of the solution. If it's on the desk next to the computer, then RS232 or USB are cheap and simple.

I connect the plc to a HMI computer (witch is a wafer lx 800, embedded pc) with a 8.4 inc touch screen, the data from the plc must then be read via Ethernet to a server with the opc and 3rd party software.

If I were pursuing an Allen-Bradley solution, I'd get a MicroLogix 1000 10-point controller, connect it to the serial port, and use Software Toolbox, KepServer, or RSLinx Single Node as the OPC server.

A Modicon solution using the Twido mini-controller could use a Software Toolbox or KepServer or other Modbus OPC Server.

I will look into both these options, thank you.

Are you building just one of these, or hundreds ? Are they going to be installed in SA or elsewhere ?

I need about 35 of these, all installed in SA. So using a full plc is not really a option, as it pushes the cost up per line. The IO count will never change, it will always be 2 inputs and one output being monitored and controlled.


What are the voltages for the Inputs and Outputs ?

All 24vdc

DDV,

Because you will require communication back to a PC, a smart relay will not be an option.

A micro PLC will probably be best. There are OPC drivers for just about any controller. You will need to determine what is best for your application.

We offer a small unit called the Smart-PAK that will also fit your application. More information can be found at www.entertron.com/smart-pak.htm Our communication protocol is ModBus RTU, for which OPC drivers are available.

Hope this helps,

God Bless,

Thank you Stephen, if the price is right, this would definitely be my solution. I will send you my details in a mail to your address provided (I hope his is in order?).

We can then take it from there.

Thank you
Dirk

PICs

Would a PIC not give you the required result?

You got me there, i would first have to google pic to understand what the hell it is.

Klink interesant!! Jogals jammer oor die krieket......

Very nice, but my electronic knowledge falls a bit short here, I don’t mind doing some development work, but this is a bit high level, at least with a plc the basics are there. Do you get a opc for this, and what software would I use for programming?



Do you have some diy projects, or diagrams?

In Midrand there's Communica, who have a PIC programming kit, which can be self assembled (minor soldering) or most electronic shops, should also come with sample app.

A PIC forms part of a lot of circuits which we are not aware of, for example DALI based dimmers and ballasts merely have PICs in them to handle the dimming and communication. DMX for stage lighting and clubs etc also utilises PICs for the comms and logic...

Worth while checking out cause if you buy, for example, a DALI based controller you're in for at least R5k. But the PIC to do the job costs +- R60.

I'm sure you can find a guy in varsity there willing to put the project together for you pretty inexpensively.

Just a thought.

example sites:
www.communica.co.za
www.electronics123.co.za (download their catalogue - they may have something in there)