Beckhoff / TwinCAT 3 opinions

Can anyone share their experiences with Beckhoff's embedded PC controllers (CX series) and TwinCAT 3? Most of my internet searches have turned up 5-year-old threads that are likely outdated.

I ran across Beckhoff at the IMTS show in Chicago last month and later went to one of their "Beckhoff in Motion" hands-on seminars. The hardware seems impressive... a sub-$1000 controller with the power of a ControlLogix, or so they claim. The whole system is built around the EtherCAT bus which I don't have experience with but it looks to have a lot of advantages. I was told that everything in the EtherCAT chain--bus couplers and servo modules included--can be replaced without any reprogramming necessary. If this is true it seems like a great benefit for 3 a.m. maintenance work. I also like the idea that the safety modules can be located in the same banks as the regular I/O.

The TwinCAT 3.1 programming software uses Microsoft's Visual Studio IDE. Being a machine programmer and not a computer programmer, I'm not sure if that's a good thing or not. It's a bit bloated but not as much as Logix 5000 IMHO. It even installed without a hitch on my 7-year-old XP laptop which was a pleasant surprise.

I bought the promo hardware package from the seminar which included a CX9020 and a few I/O modules. So I go to hook up to this thing and of course my first question is, "what's the default IP address?" This is where my dismay began with the Beckhoff online help system. I couldn't find any kind of quick start manual or any references at all to the initial configuration of the unit. Through some Internet searches I finally found that it's set up for DHCP only, so you have to run a DHCP server on your PC to initially set an IP, then you can remote to it using Microsoft's CERHOST.exe to permanently change the address. (Kudos to Archie for his YouTube videos--they're more educational than anything Beckhoff provides.)

Next problem: I try to connect from TwinCAT and I get a message that the Windows CE image is version 2.11 but I'm using TwinCAT 3.1. Off went an email to Beckhoff support and I received a prompt, detailed reply on how to download and install the updated CE image. So my first impressions of Beckhoff support (which is free BTW) are good.

Now I guess I'm going to play around with this unit for awhile. Does anyone have any suggestions for learning structured text? I have rudimentary C knowledge so I understand the concepts, I just need to learn the syntax and commands. It took me about 20 minutes of Google searching yesterday to figure out how to address an individual bit within a word variable (again, thank you Archie).

I definitely prefer twincat 3 over twincat 2 since it has all the 'tools' in one piece of software rather than two, and the environment is a little more intuitive.

However if you're used to a codesys environment, twincat 2 will be more familiar.

I really like the Beckhoff hardware, especially at their price points, it will blow anything Rockwell has out of the water.

I do think it does require more time invested to become fully versed in Beckhoff land but with free support and the ability to run your program locally on your PC... it lends itself to a self motivated individual, wanting to learn.

The way I learned structured text was to take sample programs with ST implemented and reverse engineer them.

Simply wonderful, it works really well, I've still have to master all the key shortcuts to be as productive as in TwinCAT 2, but apart of that it is really nice.

Having an editor like Visual Studio gives you plenty of advantages as it's a really mature editor full of options.

Also the new file model is great as you can import, export really easily and it gives you an easy way to integrate a source control system into your PLC/CNC programming without going through ENI (which was at least a bad product in terms of speed).

The Beckhoff approach in terms of hardware is great, Ethercat offers redundancies and high speed rates at a really small cost and their controllers are really powerful.

ST is easy depending on your background, in my case (IT background) I was set up and running in less than five minutes, but of course that will depend on your initial knowledge.

You can get samples and help from the infosystem.

Good luck!

- You don't need twincat3 to program a CX9020, you can use the old and robust twincat 2
- I think it should be possible to configure your out of the box CX9020 without setting up a dhcp server: open system manager, and then scan for units. (It's been a while since I configured a new CX9020, others may provide more details
- I too would like to have a summary of structured text self study sites. You can start by reading the free code from www.oscat.de

in twincat 2 it is the system manager and the default is in the helpfile, depending on the version used.
In twincat 3 you have to reload the internal software (as you did)
when programming you can scan the ethernet for attached machines and peripherals. you can add, them directly, and no need for tagging.
Structured text is indeed pretty simple.
as noli says, get yourself the oscat library, in three forms, the lib, the pdf and the txt.

I have used Beckhoff controllers in a few applications, with TwinCat 2.X. We used a combination of structured text and ladder logic in our implementations. The TwinCat version we used could handle any of the IEC 61131.3 languages. We selected Beckhoff controllers for the projects because of their wide range of fieldbus/communication options. A Beckhoff controller, with local I/O on the EtherCat bus or K-Bus, and the option to add a fieldbus master of many flavors is a very nice feature. The CX1000 series controllers I have used are basically an industrial Windows XP computer with a software based 61131.3 PLC built in. This is a simplification, others on the forum can probably clarify and elaborate on their capabilities. They have been reliable and durable in the equipment we have installed them in. Support has been good, Beckhoff has become our choice when needs demand a controller of greater capability than a small PLC.