Very Slow PLC Programming and Fault Finding

[DAN90 0]

Hi All, I am very to new to PLC and OPC in the production enviroment so please bare with me whilst I try to explain what my issue is. Hopefully some of you guys will know a lot more than me. I am working in a full production environment that has a range of PLCS around our production mill, each of these PLC's talk back through a 'DataHighway +' network back to a special PC on our LAN Network called the MicroLinks PC. This has the ROCKWELL OPC RSLinx Classic server software on it. So, recently I have put together a piece of .NET software in c# using the OPC .NET API to read to ROCKWELL OPC server on the Microlinks PC and sync data back into our MYSQL database that is sat on our WINDOWS R2 server PC Ever since turning on the .net software, the engineers on site have experienced a massive slow down in developing new PLC scripts and fault finding. Some of the reports are even as bad as 10 second lags. Consequently, we have had to turn of the .NET software to sync the data to allow the Engineers to do their work swiftly without issues. So i am looking for some advice on where or what i should look for, any resources to read for this type of problem etc. As PLC and networks are way out of my depth, I am just the .NET programmer. Here is the structure of our network if this is any help at all! Any advice is greatly appreciated, if you need any more information please ask!

[kaiser_will 65]

Break down the situation...you have (2) DH+ networks; both tie together into a Microlinks PC that has an OPC Server; you added a .NET program to sync data from the OPC server to a MySQL database. Once you added the .NET program on the OPC server, response of the OPC server is very slow. It sounds like the .NET program is bogging down the OPC server that it runs on. Could it be the update time of your .NET sync program is set too short and is gobbling up network bandwidth?

[Giarc 0]

I agree Kaiser, what is the network speed of your DH+ networks? Typically if they're site wide networks they're normally run at 56k or so (From what I've seen and there is reasons for that) and the max is somewhere around 230 kb/s if I remember right (None of them can keep up with Ethernet comms)..... So if you poll like crazy on your Ethernet side it can easily bog down the comms on the local networks causing them delays. Side note: I see you also have a lot of programming terminals, make sure it's common practice to go offline after they're done and save in a common location... Obviously the more connections online to each of the PLC's / HMI's the worse it will be.. You're working with dial up speeds there ;) What's your polling rate for data? Edited 17 Oct 2015 by Giarc