Hello all,
I need to connect many different brands of plc's like siemens s5-s7, ab slc5/03,mitsubishi fx2,modicon etc for data logging purposes only. I would like to do this via Ethernet to a Vb app which can log data to sql. Now if I have one pc running my vb app can I have all these drivers for different plc's running at the same time? Should I use an OPC server? It seems the more I read about layers and topologies the more confused I get.

Any help would be appreciated.

Joe

 

Use CX100 from Beckhoff or ControlLogix from Allen-Bradley. You can put multiple communication cards in these PLC's (Profibus, devicenet, ethernet, ...) Program this PLC to collect data from the other PLC's. You can use an OPC server or program a direct connection to this PLC in VB.

 

the problem is getting the hardware to get yr various plc to the ethernet. if u already have it connected, then good. if not, decide which protocol is cheaper ie hardware. i used opc for my s5 plc.

 

I have done this with both WinCC and ProTool (both Siemens products). Not necessarily those exact PLCs. With ProTool/Pro configured as an OPC client I have connected up to 8 different OPC servers on the same PC and logged the data to both Access and SQL with no problems. Of course you need to be careful with how much data you are logging and how often, but that is with any OPC server. It should be no problem with VB. If it is, then just purchase ProTool/Pro and be done with it.

Ron

 

OPC was developed to help in applications such as yours. So, yes an OPC Server is your best bet for this.

However, EtherNet may not be best suited for all of your hardware. For example, Profibus might work better for the S5 and S7 PLC's. Thankfully there are many OPC Servers available to support different network topologies that your VB app can talk to.

Also, there are currenly off the shelf data collection programs that communicate OPC and will store the information in SQL.

Contact each vendor to discuss your application or hire an outside consultant that can perform a site audit and can recommend the best solution for you.

www.gap5.com

 

Hello all,

For simpler applications you could use a Red Lion operator interface ( the new G3 Series) It will act as a protocol convertor and is easy to set up on an ethernet intranet. It can have up to Five(5) ports and can talk to a different plc on each one (plus the ethernet port). Security can be maintained to the point of having only one PC able to access the data if necessary. Find your local Red Lion Controls distributor and ask for more info.

 

In theory you could debug the different protocols and write your own communication drivers for the different PLCs. This will probably be impossible using visual basic (except for the S7). In practice it will be cheaper to use OPC.

 

Hi Joe...
Of course, you can runnig all those drivers in the same machine, The OPC Server shuold be encharger to manager interruptions and comunications times.. Be sure that you have all PLC brands drivers in your OPC Server, if it's true, don't worry it will work...

Best regards..
Jose Gonzalez
Barcelona-Venezuela

 

You'd save a lot of time & troubleshooting (but spend some money) using an OPC server that can encapsulate (or tunnel) serial prototocls directly into TCP/IP. Then a simple Ethernet-to-Serial converter can interface your PLC into Ethernet. For example this is our low-end DIN-rail unit: http://www.digi.com/products/device servers/digiOneIa.jsp

For example, Kepware at http://www.kepware.com has serial drivers for all the PLC you mention, and they can all be directed to a remote IP. (Just look for the "Supports Ethernet Encapsulation" on the protocol "Features" tab).

It is surprisingly easy to do. You'll end up paying $500-900 per protocol, but if you wrote and debugged your own drivers in VB I'd think you'd spend at least 2 weeks on each (about 80 hours or $1600 at $20/hour) plus end up with only a quarter of the functionality. Most OPC companies also offer sample VB applications to show how to read data from OPC.

- LynnL,
www.digi.com

 

Mitsubishi offers an OPC server, or MX -Component (Active X Control). You can interface either into VB. Mitsubishi's OPC allows you to drill down Mitsu networks (Melsec Net 10/CC-Link/Melsec net H/Ethernet) This will allow connection to other Mitsu PLC's that may not have a Ethernet port.

 

OPC is the obvious way to go to communicate to the various PLCs. You can purchase all the OPC servers from one company like Software Toolbox or from the individual companies. I recommend purchasing all from Software Toolbox. The support is great and there is only one phone number that you need to call.

Siemens has a new product called Industrial Data Bridge 6.0. You can use this to make the connection from the OPC Servers to the SQL Server. No need for VB and ADO programming.

Ron

 

For easy connectivity solutions from serial to ethernet, or ethernet to serial at a low cost, visit our website at http://www.comtrol.com

Comtrol was the inventor of the first multi-port serial card for PCs back in 1982 and has been first to market with industry leading technology product offerings since then.

Our DeviceMaster RTS product line offers 1, 4, 8, 16, or 32 serial ports across a single Ethernet connection. Additional details on this product can be found at the following URL: http://www.comtrol.com/products/hardware/dmrts.asp

Or feel free to contact me directly for additional information.

 

DIGI is way better than Comtrol. http://www.digi.com

 

Having used both, I lean towards the comtrol boards due to better support for Linux and extremely low resource usage.

Regards

cww