Hello All;

I need to make Profibus DP network between 8 PLCs. the used PLCs can't establish communication or initiate it in Profibus DP networks as plc work as a slave in this networks. so, now my network wihout Master, i need your suggestions. i don't have previous experiance in profibus DP.

Eng_Hassan

 

What are the PLCs? Can you assign one PLC as the Master? You cannot have a Profibus network without at least one Master and one Slave device. Also, you should visit http://www.profibus.com/pb and http://www.profibus.com/pall/meta/downloads for some literature.

Tom Chubb
JCK Automation
[email protected]
http://www.jck-automation.com

 

Hello,

if one of the 8 PLCs is a modular PLC, please ask the manufacturer for a master module and its configuration tool.

An alternative could be a PC based PROFIBUS-DP master. What you then need is a PC and a PROFIBUS DP master board and the appropriate software.

If your application needs real-time processing ... the RTOS QNX 6.4 is a perfect base for it.

Best Regards
Armin Steinhoff
http://www.steinhoff-automation.com

 

Hello Armin;

There is third party device can be connected to my PLC and work as Master called CPCI device but it's very expensive. i don't need to connect PC in my network as the propability of pc failure is large consequantly break down network, i don't need any risk in my solution.

i look for third party devise connect to my PLC serve as Master.

what is the RTOS QNX 6.4?, i need some information.

thanks for your time;

Hassan

 

Hello Tom;

My PLC is SM2 from PEP modular computer company and PEP ARAB company. this PLC work in PROFIBUS DP networks as a Slave "can't be configured to be master".

I know that netwok need at least one Master so i look for Third party device work in network as a master.

Thanks for your time,
Hassan

 

The cheapest, and possibly easiest, solution is probably a Siemens ET200s. You'd need the CPU module and the DP master:
6ES7138-4HA00-0AB0 (DP Master interface)
6ES7151-7AA20-0AB0 (also known as IM 151-7)
You might actually need the slightly more expensive processor:
6ES7138-4HA00-0AB0 (also known as IM 151-7 F)
The docs are a little unclear.

You'll also need Step 7, which is a little weirder to order.

As for using a PC, this is certainly do-able. You'll need a Profibus master card, probably in PCI form factor. Then you'll have to program the thing, which is going to be more painful. The suggestion of using QNX for this is ludicrous; the cost of the development license alone is prohibitive, but that's nothing compared to the learning curve.

The last suggestion is to hire somebody to do this for you, and let THEM worry about the implementation. In this case, if they chose QNX or anything else it's fine. Hiring an integration company that knows how they'd do this already (regardless of the actual implementation) may give you sticker shock when you first look at the quote, but it's probably cheaper than muddling through this on your own.

-James Ingraham
Sage Automation, Inc.

 

> There is third party device can be connected to my PLC and work as Master called CPCI device but it's very expensive. i don't need to connect PC in my network as the propability of pc failure is large consequantly break down network, i don't need any risk in my solution. <

A good and robust PC hardware (e.g. PC/104plus .. ) together with a reliable real-time operation system like QNX 6.4 is a secure solution.

Our customers have comparable installations running in the field without problems ( e.g. steel production: QNX DP master/ several Siemens S5-95U PLCs, power generation at ground control stations of the ESA: QNX DP master / ET200 slaves, are running since years without rebooting)

> what is the RTOS QNX 6.4?, i need some information. <

Please have a look to http://www.qnx.com. QNX 6.x is available as an open source system. You can recompile e.g the kernel, the networking system and the file system. For the development of C applications is available the IDE Momentics (Eclipse based). As an alternative, we offer a real-time soft PLC which can be programmed visually with an IEC 61131-3 like tool (
http://www.steinhoff-automation.com/Programming.htm,
http://www.steinhoff-automation.com/HMI.htm ). This real-time soft PLC supports e.g. event oriented processing, the development of complex visualization applications and message passing for multi target applications.

Best Regards

Armin Steinhoff
http://www.steinhoff-automation.com

 

Hello,

> The cheapest, and possibly easiest, solution is probably a Siemens ET200s. You'd need the CPU module and the DP master:
6ES7138-4HA00-0AB0 (DP Master interface)
6ES7151-7AA20-0AB0 (also known as IM 151-7)
You might actually need the slightly more expensive processor:
6ES7138-4HA00-0AB0 (also known as IM 151-7 F) <

The IM 151 and the ET200s are a slave modules and can't be used as a master.

> You'll also need Step 7, which is a little weirder to order. <

IMHO, the ordering is simple if you have chosen the right PLC

> As for using a PC, this is certainly do-able. You'll need a Profibus master card, probably in PCI form factor. Then you'll have to program the thing, which is going to be more painful. <

Do you have any experiences with such a solution? The programming of
a PC based PROFIBUS application is really simple.

> The suggestion of using QNX for this is ludicrous; <

If this would be the case, we would have a lot of ludicrous customers

BTW, there is a "ludicrous" installation at the Walt Disney / Epcot. It's the Mission Space ride ... it's working with 12 QNX PCs and 12 Interbus networks.

> the cost of the development license alone is prohibitive, but that's nothing compared to the learning curve. <

No, no ... QNX 6.x is one of the best documented RTOS! The development IDE is based on Eclipse which is really easy to handle. We can also provide an alternative for the plain C programming by our graphical programming tool for our real-time soft PLC. This solution is also very cost effective and offers a higher functionality than Step 7.

> The last suggestion is to hire somebody to do this for you, and let THEM worry about the implementation. In this case, if they chose QNX or anything else it's fine. Hiring an integration company that knows how they'd do this already (regardless of the actual implementation) may give you sticker shock when you first look at the quote, but it's probably cheaper than muddling through this on your own. <

Yes, with an experienced partner the integration is really easy.

Best Regards
Armin Steinhoff
http://www.steinhoff-automation.com

 

Armin-

The 6ES7138-4HA00-0AB0 module I called out is in fact a DP Master controller for IM 151 / ET200s. However, if I've blown this by mis-understanding, an S7-300 315-2DP, 315-2PN/DO or 313C-2DP would also do the trick.

>IMHO, the ordering [for Step 7] is simple if you have chosen the right PLC <

Well, language is one thing, and you have to decide what kind of license. That made it difficult for me to just paste in a part number.

>Do you have any experiences with [programming PC pased Profibus applications]? The programming of a PC based PROFIBUS application is really simple. <

Yes, I do. For me, it's quite easy. But I have a development seat set up, and example projects to draw from, and several different vendors of Profibus cards I've used. As opposed to never having HEARD of QNX, or trying to decide whether to use Windows/Linux/QNX/VxWorks/ etc. Not to mention which language, API, development environment...

>> The suggestion of using QNX for this is ludicrous; <<

>If this would be the case, we would have a lot of ludicrous customers <

I imagine that you have dev seats already, and you do projects in QNX. I meant that starting from scratch for a one-off project is ludicrous. The cost of a dev set alone is over eight thousand US dollars. And you'd better know C. And it would help if you're at least familiar with *nix.

>BTW, there is a "ludicrous" installation at the Walt Disney/Epcot. It's the Mission Space ride. it's working with 12 QNX PCs and 12 Interbus networks. <

It's not that QNX is ludicrous. 12 QNX PCs and 12 Interbus networks sounds like a good fit. The International Space Station runs QNX. There are lots of cars that run QNX. It's a great OS. But using it for this is like using a B2 bomber to kill a cockroach.

>No, no. QNX 6.x is one of the best documented RTOS! <

It doesn't matter how well it's documented. You still have to learn how to build boot files, how to strip unneccssary files, what "ls" means, how to auto-login, how to lock down security... Starting cold on QNX (or any RTOS) is going to be a steep learning curve.

>The development IDE is based on Eclipse which is really easy to handle. <

Sort of. You still have to get used to the idea of cross-compiling, which is not natural for most people who have never heard of an RTOS. You could self-host, of course, which is one of the reasons I love QNX. But then Eclipse is horrible self-hosted, so you're back to command line tools and a terrible editor. I actually wrote my own editor for QNX / Photon in Java / SWT because ped sucks and Eclipse is so awful when self-hosted, and we don't see any point in using QNX if we're not going to self-host.

>We can also provide an alternative for the plain C programming by our graphical programming tool for our real-time soft PLC. This solution is also very cost effective and offers a higher functionality than Step 7. <

This sounds like a much more reasonable suggestion. At this point, the guy doesn't care WHAT'S inside the little black box, just like wtih Siemens or whatever. The fact that it's QNX becomes irrelevant.

>Yes, with an experienced partner the integration is really easy. <

We agree on something, at least.

-James Ingraham
Sage Automation, Inc.

 

Hello,

> The 6ES7138-4HA00-0AB0 module I called out is in fact a DP Master controller for IM 151 / ET200s. <

ET200 devices are normally slave devices. An exception is the IM-151-7 of the ET200 devices. it is a CPU =:-/ . Yes, you are right and for this CPU is indeed a master controller available. it a little bit confusing.

> [ clip ]
I imagine that you have dev seats already, and you do projects in QNX. I meant that starting from scratch for a one-off project is ludicrous. The cost of a dev set alone is over eight thousand US dollars. And you'd better know C. And it would help if you're at least familiar with *nix. <

What is the price of Step 7? It takes also time to learn to program with that IEC61131-3 tool.

>> BTW, there is a "ludicrous" installation at the Walt Disney/Epcot. It's the Mission Space ride. it's working with 12 QNX PCs and 12 Interbus networks. <<

> It's not that QNX is ludicrous. 12 QNX PCs and 12 Interbus networks sounds like a good fit. The International Space Station runs QNX. There are lots of cars that run QNX. It's a great OS. But using it for this is like using a B2 bomber to kill a cockroach. <

IMHO, that's also true for Step 7...

[ clip]

> Sort of. You still have to get used to the idea of cross-compiling, which is not natural for most people who have never heard of an RTOS. You could self-host, of course, which is one of the reasons I love QNX. But then Eclipse is horrible self-hosted, so you're back to command line tools and a terrible editor. I actually wrote my own editor for QNX / Photon in Java / SWT because ped <

OK ... I would never call 'ped' an editor But with the X11 server "Xphoton" you have access to a lot of X11 based applications and editors like Nedit and SciTE. Together with the debugging tool "ddd" it is an acceptable self hosted development environment.

If you want to use Eclipse self hosted you need a big and fast machine.

> sucks and Eclipse is so awful when self-hosted, and we don't see any point in using QNX if we're not going to self-host. <

>> We can also provide an alternative for the plain C programming by our graphical programming tool for our real-time soft PLC. This solution is also very cost effective and offers a higher functionality than Step 7. <<

> This sounds like a much more reasonable suggestion. At this point, the guy doesn't care WHAT'S inside the little black box, just like wtih Siemens or whatever. The fact that it's QNX becomes irrelevant. <

Yes, it's possible to write e.g. interrupt service routines without
knowing something about QNX.

Best Regards
Armin Steinhoff
http://www.steinhoff-automation.com

 

>What is the price of Step 7? It takes also time to learn to program with that IEC61131-3 tool. <

Step 7 is a little over two thousand USD. Still noticeably cheaper than a single QNX dev seat.

Yes, Step 7 (like any IEC 61131-3 tool) has a learning curve. And I *HATE* Step 7. (You can search for some of my comments about it on here.) But it's still going to be a way less difficult solution from a standing start on the described problem.

>OK ... I would never call 'ped' an editor <

Something else we agree on!

>But with the X11 server "Xphoton"... <

I had terrible luck with Xphoton. It's huge, slow, unwieldy, and unreliable. With the death of the 3rd Party CD it became next to useless. Things may have gotten better now with pkgsrc... but the official line from QNX on X packages with in pkgsrc is "you probably don't want to use this."

>Together with the debugging tool "ddd"... <

I had particular trouble with ddd under Xphoton. We just use printf debugging most of the time, with plain-old gdb when we're in a real pinch.

>Yes, it's possible to write e.g. interrupt service routines without knowing something about QNX. <

I don't think I understand your point here. I can't imagine writing ISRs without knowing a LOT about QNX.

-James Ingraham
Sage Automation, Inc.

 

Hello,

>> What is the price of Step 7? <<

> Step 7 is a little over two thousand USD. Still noticeably cheaper than a single QNX dev seat. <

Thanks. Is it correct that the price depends on the target PLC ? The price of DACHSview is lower than the price of Step 7 and is independent to the target PC.

> I had terrible luck with Xphoton. It's huge, slow, unwieldy, and unreliable. <

Sorry, the last version of XPhoton has an excellent performance and isn't slow, unwieldy and unreliable ... did I miss a negative ttribute? . (I have to correct myself: the first version of "XPhoton" was called "Xphoton" and was really bad ... the powerful open source version is called "XPhoton")

Under QNX6.4 e.g. I'm using the window of "ddd" redirected to a LINUX machine ... and it works reliable, fast and better then the debugger of Eclipse.

In general, the performance of XPhoton depends on the Photon driver and its video card. Your statement can only be correct if Photon was using a video card which has really low performance.

> With the death of the 3rd Party CD it became next to useless. <

This version from the 3rd Party CD works with QNX 6.4. what's the
problem? However, XPhoton is open source. You can port it to the newest Photon version if necessary.

> Things may have gotten better now with pkgsrc... but the official line from QNX on X packages with in pkgsrc is "you probably don't want to use this." <

The package manager "pkgsrc" will help you with the installation of application packages and with the distribution of applications. But it doesn't help for the development of applications ... I don't see your point here.

> I had particular trouble with ddd under Xphoton. We just use printf debugging most of the time, with plain-old gdb when we're in a real pinch. <

"Debugging" with printf statements isn't really the status quo of the self hosted development environment of QNX6 (or the old QNX4).

The current version of the self-hosted Momentics (QNX6.4) works for us really fast and flawless on top of a dual core PC with 1GByte memory (~EUR 300). IMHO, your problems are probably problems from yesterday.

> I don't think I understand your point here. I can't imagine writing ISRs without knowing a LOT about QNX. <

It's simple ... you have just to learn the usage and semantic of three function blocks: InterruptAttachEvent, InterruptAttach and
InterruptWait. That's all. (DACHSview works event oriented. Events can be hardware interrupts, IPC messages, semaphores and signals, access to physical memory and I/Oports is supported)

Best Regards
Armin Steinhoff
http://www.steinhoff-automation.com