most recent 30 from http://controlsoverload.com 2010-09-06T10:58:46Z http://controlsoverload.com/feeds/question/99 http://www.creativecommons.org/licenses/by-nc/2.5/rdf http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc Scott Whitlock 2009-12-07T18:02:40Z 2010-03-19T18:42:29Z

<p>I'm already aware of OPC for pulling data from a PLC, but I wanted to know what other alternatives existed that didn't require an OPC server in the middle. Assume we're trying to pull the data into a database server (like SQL) or into a PC application.</p>

http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc/100#100 unknown (google) 2009-12-07T18:52:17Z 2009-12-07T18:52:17Z

<p>Well you have to have somthing that can communicate to the PLC so you would need a dll that you can use to write code against. There are a few vendoes that do ActiveX controlls or dll's for communication. Some protocols are simple enough that you could actually impliment your own code to talk to the device. If y ou do a google search for ActiveX Automation device communicaitons you will find them.</p> <p>Keep in mind that you are coing to have to all the communicaitons management that the communications portion of the OPC server would have done and you are going to have have your own error handling.</p>

http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc/101#101 Scott Whitlock 2009-12-07T19:17:41Z 2009-12-07T19:17:41Z

<p>One I've used before (for Allen-Bradley) is <a href="http://www.ingeardrivers.com/allen%5Fbradley/allen%5Fbradley.htm" rel="nofollow">Cimquest In-Gear</a>. It worked well. I know they also have connectors for GE-Link, but their Omron driver appears to be OPC based. I'm interested in other specific alternatives, and your reviews if possible.</p>

http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc/102#102 Luis R 2009-12-08T03:08:06Z 2009-12-08T03:08:06Z

<p>Depending on the type of PLC you are using, one option would be using an HMI to act as a OPC Driver. It is possible to use an HMI Tag and Microsoft Excel DDE, with a little bit of help from VBA. I doesn't work as well as an OPC Server and much more limited. </p>

http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc/150#150 Nick Clute 2009-12-11T23:28:11Z 2009-12-11T23:28:11Z

<p>One of the ways that I've suggested to do this is to use Modbus TCP/IP, you can implement a Modbus Master in a PC Application pretty quickly using standard sample code found on the net. Of course, this also requires the PLC to support Modbus, but most are capable (I even saw some sample code the other day which allows Siemens to talk Modbus...crazy.)</p>

http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc/161#161 Jon Mills 2009-12-18T06:04:53Z 2009-12-18T06:04:53Z

<p>I'd second Nick's vote for Modbus/TCP.</p> <p>We use it all the time with our custom controllers.</p> <p>There's plenty of Master (client) code around on the net.</p> <p>I've personally written several Modbus/TCP clients in Python using the Twisted network library.</p>

http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc/164#164 Mauli 2009-12-18T09:05:32Z 2009-12-18T09:05:32Z

<p>There is always <a href="http://www.openscada.org/" rel="nofollow">OpenSCADA</a> if you are on the Java platform. The website is a bit of a mess at the moment (we are working on it), but if you are interested, just drop us line (info AT inavare DOT net)</p> <p>There is a standalone project to talk to a OPC server written in pure java (Utgard project) which is already in use for quite some time.</p> <p>And we have a brand new implementation of the dave protocol (S7) in pure Java (no dlls required, so it works just fine on linux!) which will be used in some of our projects (although we are not sure at the moment under which kind of license it will be available, if you are interested just let us know).</p> <p>Full disclosure: I'm one of the developers of OpenSCADA</p>

http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc/200#200 Jens Reimann 2010-01-18T08:23:48Z 2010-01-18T08:23:48Z

<p>There are several ways of communicating with a PLC. Depending on your PLC of course ;-)</p> <p>Possible solutions should be:</p> <ul> <li>Modbus (both RTU and TCP)</li> <li>Dave (for Siemens PLC)</li> <li>IEC60870</li> <li>A custom protocol developed for both PLC and host system</li> </ul>

http://controlsoverload.com/questions/99/what-alternatives-are-there-instead-of-opc-for-pulling-data-from-a-plc/227#227 Joe A 2010-03-19T07:28:07Z 2010-03-19T18:42:29Z

<p>I justed finished an application that had these exact requirements with an Omron PLC.</p> <p>Check out <a href="http://www.plclibrary.com" rel="nofollow">www.plclibrary.com</a></p> <p>I believe it is exactly what you are looking for ... and relatively cheap!</p>