Data Extraction from PLCs

Hi Guys,

We are designing a Decision Support System and as a part of the process we need to capture the data from PLCs. Is it possible to generate flat files of the data captured in the PLCs and load it into a database. Do PLCs have any protocol through which they can interface with the computer?

Any pointers in this regard would be really useful

cheers
neil

Generally YES.

What PLC are you talking about?

Mike is correct. The answer is almost certainly yes. Almost all PLC's have OPC software drivers available for a range of OS's. Once you have an OPC driver installed and tested then you have a range of choices about how to move the data from the OPC server, to the relational database.

The best way to do this is very dependent on how much data you need to store, how often, the relational database that is the destination, how critical the data is, and what your budget is.

There are many SCADA packages with a datalogging feature that will put the data into a simple .dbf format or similar. Once data is collected into a .dbf file it can be merged it a larger "decision support system" at your leisure.

A higher level solution is to use a software package like RSSql, which Rockwell Software's transactional database tool. RSSql Info .

The merit of this kind of solution is speed, security and ease of use, especially by IT people, who tend to find working directly working with PLC controls technology and software, rather baffling. This is just the package I am familiar with; I am sure others in this forum will have used others. Of course it may also be a total overkill for what you need. In order to give good advice we about your application, we will need better information about it.

Hello,

According the message of Philip I used four other SCADA softwares to do datalogging.

1. Intouch (Wonderware) with an Siemens S7-300. Data communication with an SQLServer.

2. WinCC (ver6) (Siemens) with an Siemens S7-300. Data communication
with an SQLServer.

3. Citect with an Siemens S7-300. Data communication with an SQLServer.

4. Delta-V via an applicomcard. Datacommunication with Excel and an PI-Server.

So you see it can be done and if I might add it's rather simple.

Rudi

Just to add to Philip's comments about RSSql; it doesn't do any visualisation in the way that the SCADA products do (no nice pictures of your equipment running) and because of this it's usually much cheaper to implement. All you need in addition to RSSql is an OPC driver (available either from the PLC manufacturer or a third-party such as Kepware) and a database. RSSql's got a fairly easy configuration wizard, you should get set up in a couple of minutes provided that the tables are already configured in your database.

It's not the only solution but don't disregard it just because you're not using AB PLC's

Thanks for quick responce.
Brief about application: I have a Siemens Crane Management software (SiCMA) at centralised place. This is already configured and receiving data from various field Crane PLCs in field. There is local Desktop with WinCC at field directly communicating with Crane PLC. The field desktop is having its local SQL database.
Field data is pushed in central database using SiCMA configuration.

My question is whtout touching SiCMA software. Can i get one set of parameters from PLCs at field to another database at centralised place?
I it possible to connect TWO diffeent databases (SQL and Oracle) to receive data from same PLCs? How can i get it done?

Fritz_frederix said:

Hello,

According the message of Philip I used four other SCADA softwares to do datalogging.

1. Intouch (Wonderware) with an Siemens S7-300. Data communication with an SQLServer.

2. WinCC (ver6) (Siemens) with an Siemens S7-300. Data communication
with an SQLServer.

3. Citect with an Siemens S7-300. Data communication with an SQLServer.

4. Delta-V via an applicomcard. Datacommunication with Excel and an PI-Server.

So you see it can be done and if I might add it's rather simple.

Rudi

Click to expand...

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Thanks Rudi for quick response.
Brief about application: I have a Siemens Crane Management software (SiCMA) at centralised place. This is already configured and receiving data from various field Crane PLCs in field. There is local Desktop with WinCC at field directly communicating with Crane PLC. The field desktop is having its local SQL database.
Field data is pushed in central database using SiCMA configuration.

My question is whtout touching SiCMA software. Can i get one set of parameters from PLCs at field to another database at centralised place?
I it possible to connect TWO diffeent databases (SQL and Oracle) to receive data from same PLCs? How can i get it done?