Demo Software OPC Error

I downloaded and installed the FactorySQL software but the OPC server would not load I get an error message saying
“Download Failed: Server did not specify content length”

What have I done wrong?
Do I need to purchase FactorySQL before I can download it?


A few questions:

  1. What OPC Server are you using?
  2. Are you able to browse the OPC Server in the top left pane
  3. Describe what you did to get the error message.

You do not need to purchase FactorySQL. You can download it here.

The trial is fully functional. Groups will automatically stop running after 2 hours. You may restart them as many times as you’d like.

1.) That is the problem I was trying to install the KepServerEX that is in the Demo executable and I get the error message.

Sounds simply like a problem with the actual file transfer. The installer for FactorySQL simply downloads kepware when that installation option is selected, it is not “bundled” into the FactorySQL install file.

If you’ve tried a couple times with no luck, I’d recommend going over to and trying to download it directly from them.


Is this a free download? Or do I need to purchase the driver for each PLC type.

Kepware has a demo available, but the actual drivers have various prices. The simulator, however, is free.

What type of PLC are you trying to connect to? If you’re just interested in playing around with FactorySQL, I’d recommend you go download kepware and install it with the default options, which will only include the simulator. If you have some actual equipment you want to talk to, you can either start with the kepware demo and eventually buy the driver, or look around and see if you can find a cheaper/free opc server.


Kepware’s KepServerEx has a fully functional 2 hour limited runtime demo like FactorySQL and FactoryPMI. Click here to download

Once you get the hang of the OPC simulator, you can evaluate Kepware’s software for free. Their pricing is very fair.