CoDeSys. What do you think ?

[CharlesM]

Is this the same as the Wago stuff? I have never done any of it but this is a good post. I like the screen shots. A picture is worth a 1000 words.

 

[JesperMP]

I have a lot of experience with AB and Omron also. But I will say that if the control system is quite advanced, I much prefer to use TwinCAT.

If CoDeSys is as good as or better than RSLogix, then that is the best recommendation it can get.

I'm encouraged that others here are using CoDeSys. I hadn't known it was spreading this much.

I think that Beckhoff is the most important CoDeSys partner, and Beckhoff has growth rates around 20-30% per year. But with approx 800 employees they are still dwarved by the big automation players.
Actually I am amazed that they can have such a product portfolio with only so few people.

Is this the same as the Wago stuff?

Yes, I believe that Wago also uses CoDeSys.

 

[JesperMP]

More curious.

Now I have gotten a complete price list from Beckhoff. I have to say, the prices are shockingly low !
The more that I look at the stuff, the better it seems.
I like that the programming is open standard IEC601131-3.
I like that you can have ethernet in even the smallest PLCs.
I like that the hardware catalog scales well from the smallest to the biggest.
I like the blade-style terminal i/o blocks.
I like the plethora of supported bus standards.
And did I mention the low prices ?
To me, it seems that Beckhoff is cheaper than even AD, but with Beckhoff you can take on even the most demanding project that you cannot with AD.
Is there a catch ?

Thus I have more questions about CoDeSys/Beckhoff.

What is the build quality ?
What is the reliability ?
Do you get discounts on the list prices ?
How is hardware diagnostics, for example compared against STEP7 (which I consider very good) ?
How is online programming like ?
Is it true that when downloading code to an already running PLC (online change), that the entire program is downloaded to flash, and thus the effective max program size is halved ?
How performant is the Beckhoff PLCs you have used ?
How much memory is used for code and data, relative to S7 ?
How performant is ethernet networking (via the regular ethernet ports, not via Ethercat) ?
For the CPUs without a CF slot, is there a way to load the program without the programming software ?
For the CPUs with a CF slot, can you load a new program via a CF card ?

Thanks.

 

[Joe_WaZoo]

I am going to TURCK to get training on CoDeSys in June as they too will be offering this capability in their BL67 & BL20 I/O products.

Joe_WaZoo

 

[Archie]

I'll give these my best shot:

What is the build quality ?
Not sure what you are asking on this

What is the reliability ?
Quite high for the systems that I have done. On PC based control, reliability is a factor of how many other uses the PC has. The more software loaded, the more chance of problems.

Do you get discounts on the list prices ?
Yes

How is hardware diagnostics, for example compared against STEP7 (which I consider very good) ?
Quite a number of ways. Flashing lights, diagnostic codes in System Manager are a couple ways

How is online programming like ?
A little different than most others. The changes are made offline, then you log in to send the changes.

Is it true that when downloading code to an already running PLC (online change), that the entire program is downloaded to flash, and thus the effective max program size is halved ?
Not sure about this one. My largest program I had written was on a PC based system where memory is generally not an issue.

How performant is the Beckhoff PLCs you have used ?
The CX1000 series has proven to be a very good performer. I have not used the newer processor with higher speeds such as the 1Ghz, so I can only figure if 266MHz did well, the 1GHz will be much better.

How much memory is used for code and data, relative to S7 ?
Have not used S7 for a fair comparison

How performant is ethernet networking (via the regular ethernet ports, not via Ethercat) ?
Does well in my opionion. I've used real time ethernet with 22 slave nodes with no problem and can get online over the same network without any noticable degradation. Have not used the EtherCAT yet.

For the CPUs without a CF slot, is there a way to load the program without the programming software ?
Not that I am aware of. But this may not be an issue since the software is a free download with a 30 day trial on the runtime. If the 30 days expire, the programming environment indefinitely works for remote systems such as a CX1000.

For the CPUs with a CF slot, can you load a new program via a CF card ?
Have not tried it, but the boot project is nothing more than a file, so I would't see why you couldn't copy a new boot project on the flash card.

 

[JesperMP]

Hi Archie.
I really apreciate your input

What is the build quality ?
Not sure what you are asking on this

Does it look/feel like cheap chinese merchandise ?
Or does it look/feel like a quality product ?
Does the parts snap into place like or do you have to use a hammer ?

Do you get discounts on the list prices ?
Yes

Wow ! I sort of guessed that thair list prices were fixed considering how low they are already.

How performant is the Beckhoff PLCs you have used ?
The CX1000 series has proven to be a very good performer. I have not used the newer processor with higher speeds such as the 1Ghz, so I can only figure if 266MHz did well, the 1GHz will be much better.

I should have asked differently. The problem is that there are zero information on instruction execution times. I have no idea how good they are performance wise.

How much memory is used for code and data, relative to S7 ?
Have not used S7 for a fair comparison

Same as the previous question. What are the memory requirements, instructions for instruction.

For the CPUs with a CF slot, can you load a new program via a CF card ?
Have not tried it, but the boot project is nothing more than a file, so I would't see why you couldn't copy a new boot project on the flash card.

That will require some means to give commands to the CPU. I know that you can add a DVI/USB module, but without such a module how do you do this ? With the little keypad and display on the PSU ?

Thanks !

 

[Archie]

Does it look/feel like cheap chinese merchandise ?
Or does it look/feel like a quality product ?
Does the parts snap into place like or do you have to use a hammer ?

I would have to say their hardware does have a fairly solid feel to it. In comparision, I've used some of the modular PLC's from Automation Direct and they felt like they were going to crumble when it was put together. Beckhoff definitely does NOT feel like it will break by normal use. They go together nicely and pull apart fairly easily.
They recently released terminals with removable terminal blocks making it easier to relace terminals.

I should have asked differently. The problem is that there are zero information on instruction execution times. I have no idea how good they are performance wise.

Same as the previous question. What are the memory requirements, instructions for instruction.

That will require some means to give commands to the CPU. I know that you can add a DVI/USB module, but without such a module how do you do this ? With the little keypad and display on the PSU ?

My guess is that since it can be PC based there are too many CPU speed possibilities to try to give execution times on a per instruction basis. One big difference between TwinCAT and typical PLC's is that TwinCAT is actually a compiled language and not interpreted.
Per the IEC61131 specs, the scan rate is set to a fixed value(typically 10ms). The program scans once every scan time and the rest is CPU idle time. TwinCAT reports the amount of CPU time required.
The largest program I have written compiled to about 500k of code and scans every 10ms and uses about 3-4% CPU time on a 1GHz processor. In theory, the program could be 20 times the size without reaching the CPU limit of 80%, which is set in TwinCAT.

I quickly did a test on memory usage and it looks like each basic ladder instruction uses one byte (contacts & coils). A timer uses 16 bytes. Keep in mind that memory is configurable in TwinCAT. You can change the amount that gets used for the program and data. It is a very scalable system.

As for communication, I always use ethernet for downloading programs. The older series of controllers (BC Series) you can use the serial cable. But I would recommend avoiding the BC series because it does have some limitations.

 

[JesperMP]

Per the IEC61131 specs, the scan rate is set to a fixed value(typically 10ms). The program scans once every scan time and the rest is CPU idle time.

Still, that is just another way of asking the same question.
In stead of asking what cycle time you get with a certain amount of code, with IEC61131-3 you ask how much code you can write before you hit the ceiling.

TwinCAT reports the amount of CPU time required.

So one could try to write some code and then TwinCat will tell you the minimum scan rate. And this varies with the CPU used ?

I quickly did a test on memory usage and it looks like each basic ladder instruction uses one byte (contacts & coils).

That sounds as it is pretty frugal with the memory.

As for communication, I always use ethernet for downloading programs. The older series of controllers (BC Series) you can use the serial cable. But I would recommend avoiding the BC series because it does have some limitations.

What are these limitations ?
And yes, I love that you can get ethernet with even the smallest CPUs.
I was looking at the BX9000. It looks very well equipped at a very low price. And they have announced BC9050 at a rock bottom price, also with an ethernet port.
For bigger projects I would go straight for the CX1020.

You dont know about that about how to load the program from a CF card ?
We are an OEM company that have customers all over the world, and I am accustomed to being able to send EPROMs with program updates.

 

[Peter Nachtwey]

I quickly did a test on memory usage and it looks like each basic ladder instruction uses one byte (contacts & coils).

This isn't possible.

 

[Archie]

Still, that is just another way of asking the same question.
In stead of asking what cycle time you get with a certain amount of code, with IEC61131-3 you ask how much code you can write before you hit the ceiling.
So one could try to write some code and then TwinCat will tell you the minimum scan rate. And this varies with the CPU used ?
That sounds as it is pretty frugal with the memory.
What are these limitations ?

It would actually be more like, you write the code, then lower the scan rate to a point that is toleratable for CPU usage. On PC based, the more CPU time the control program uses, the less responsive the other program will be and things like mouse and keyboard input.
The most intensive application I saw was on a large stamping press with a large program and they had it scanning at 2ms. This pushed the CPU usage up to around 50%. If this becomes a problem then it is only a matter of moving to a faster processor which in effect will lower the CPU usage.


Peter,

I do stand corrected. My quick test was not very scientific, just quick and dirty. I looked at the wrong value when I figured memory usage for the program. So I am not really sure how to come up with a way to figure usage on a per instruction basis.

I can say that it will take a massive program before you run into any memory issues. One exception would be the BC series, and hence another reason I recommend avoiding that line unless it is a very small machine.

 

[ndzied1]

FYI, there is a CoDeSys forum at:

http://forum-en.3s-software.com/

but it doesn't get anywhere near the traffic that this site gets.

 

[Jon R]

I asked about Beckhoff stuff on this site a few months ago now(more specifically the hardware than software) and I seem to remember a couple of fairly negative reactions.

If they are growing at the rate that Jesper has mentioned then I can't see that there can be too much wrong with their kit.

And yes they do a phenomenal range. I have looked at for a couple of projects and compares very well on price with ordinary PLC manufacturers.


Jon.

 

[JesperMP]

Hi Jon R.

Prompted by your post, I did a search for Beckhoff and read a lot of the findings. I should have done that initially.

I have to say that the verdict is split.
Some posters rave about Beckhoff and has nothing but praise.
Others have only have complaints and will never use Beckhoff again.
I think that most of the complaints are when using IPCs, only one complains about the bus terminals.
What is frightening is that those people with complaints about reliablity also complain about bad support. The possitive posters praises both reliability and support.

Personally I am thinking about using their embedded PCs (not the IPCs) in the CX9000 or CX1020 ranges. And I will only use them for regular PLC jobs, no other programs will run on the CPUs.
To be honest, the chance of my company switching from the big automation players to a minor player is practically nil, but I am following the development with interest.

 

[hokie]

The code size for codesys is very efficent because the compiler compiles the logic directly into machine code and downloads it straight into RAM.
You should be able to see task execution times on the root of the task configuration screen when online(if you are using tasks instead of the PLC_PRG) if you have the right libraries added(syslibtime and systaskinfo). In most systems they are added by default. Can't speak for the Beckhoff system though.

 

[PhilipW]

How does Codesys handle "online editing"?