Profibus network problem

I'm trying to set up a Profibus network between a CPU315-2DP (master) and a CPU314C-2DP (slave).
I've got great problems.
1. For the master:
when I'm configuring the hardware: I add the master, I add the Profibus network. If I download the hardware configuraton now, then there is no problem. If I add a slave to the Profibus network (the CPU314C-2DP) and download the configuration again, then immediately the SF LED goes on and the Bus LED starts to blink. Why? I haven't even downloaded OB1 and the PLC is in Stop Mode.
2.For the slave:
When I configure the CPU314C-2DP as a Profibus DP Slave and download the configuration to it then again the SF LED goes on and the Bus LED blinks.
Can someone help me?
Thanks a lot!

See this project: View attachment Master_s.zip. You should have OB82,85,86,122 in your program so your plcs not to stop.
With this project if there is no additional moduls and cpu's are with the same serial numbers and wires are ok and so on, it should work.

Why do I need OB82,85,86,122 for the Profibus network?

werder85 read your private messages - i've sugested you some advices

I've added OB82, OB85, OB86 and OB122. Still the same.
I've attached a printscreen of the diagnose buffer.
What else can I try?

How do you have the PC and two PLCs connected.
Do you have the PC connected to the Master's MPI port
and the two PLC's Profibus ports connected toghether?

That's exactly how it is!

Have you tried that project that dimmarkov posted. If the connections are correct that project should work. It might help narrow down where your problem is.

You may get some red lights after the projects first load but they should pretty quickly go green.

Can you post an archive of your project?

I've tried that project, but when I open it, I get some errors, and then when looking at the hardware configuration, there is no CPU in it.
I've uploaded my two projects (I know I should've put them in the same project but when I created them, I didn't have that in mind. I don't think it's a problem).
Another question: when I download the project to the master, immediately after the hardware config. is downloaded, the SF LED goes on and the BF blinks. Is it possible that they go off afterwards, if the communication is established?
Thanks a lot!

Communication problem

Hi ,
As to the Diagnostic buffer try out your Profibus Communication first Since the synchronization problem with I/Os i can see.

Hi,
may be your problem is in your hardware catalog - update it (Use PLC with exactly serial numbers for your project).
This may be the reason why you can't open my project, too.
If you want to see your project select language neutral in properties of the projects.
and is much easy to configured your project corect if you do everything in one project this is another possible reason for your problem.

I don't think you can get the two PLC's talking with the project like that.
It actually assigns two different Profibus networks to each PLC.

You should have both of them in the same project.

If you open up the hardware configuration for each one, double-click the DP line, keep hitting properties buttons until you can look at the S7 subnet ID. ITs different in the two projects. These two PLC's can't talk like that.

Just put two station objects in one project.
Configure the hardware for the slave and configure it as a DP slave.
When you add the slave processor in the hardware configuration, just give it a Profibus address, don't assign a subnet yet.
Double-click the DP line under the processor. On the box that opens, select the operating mode tab and configure this one as a slave.
Compile it and close it.

Configure the hardware for the master.
When you add the processor, assign the address, and this time go ahead and assign a new network. When you do this you should get the network line to appear. The processor should already be defined as a master by default.

To add the slave to the same DP network as the master:
Open the Profibus-DP folder
Open the Configured Stations folder
Drag the CPU 31x object onto the DP master system line.
A box should popup with the slave that you configured.
Select the slave and click the Connect button. It should ask if you want to add it to the network. Add it.

Now if you go into each station object, add the error blocks (OB82 and OB86)..

Download each station object through the individual CPU's MPI port and they should be ready to go.

THis should get the network to start up.

Get this part to work and then you can worry about getting the data flow between the two.

Thanks a lot for your help!
When trying to follow the steps you described, I got stuck twice:
1. You said:
"
Configure the hardware for the slave and configure it as a DP slave.
When you add the slave processor in the hardware configuration, just give it a Profibus address, don't assign a subnet yet.
Double-click the DP line under the processor. On the box that opens, select the operating mode tab and configure this one as a slave.
Compile it and close it.
"
If I do this, I get an error at compilation. I added a printscreen as an attach. (I get rid of the error only if I assign a subnet)
2.Where is the Profibus-DP folder? and then the Configured Stations folder?

When configuring the 314C's DP port, I think you forgot to connect it by selecting a Profibus network, or creating a new Profibus network.
That is why you get the error "No Profibus network assigned to the CPU in rack 0 slot 2".

tim's description is pretty good. If you follow it exactly you will succeed.

I have attached a sample project (but it is better if you figure out to follow tims guide):

werder85 said:

If I do this, I get an error at compilation. I added a printscreen as an attach. (I get rid of the error only if I assign a subnet)
2.Where is the Profibus-DP folder? and then the Configured Stations folder?

Click to expand...

I should have mentioned that error screen. It pops up, but if you just ignore it and go on things will work.

You may get a similar message after you configure everything in the master's hardware configuration because you will not have setup any shared addresses yet. Don't worry about that part yet, you can do that after you get the network to turn on without any red lights.

The Profibus-DP folder is in the hardware catalog, where you normally add the power supplies, cpus, and digital I/O modules from. It should be listed up at the top of the hardware catalog. If the catalog isn't showing there is a toolbar button you can click to open it up again.

This isn't the most straightforward thing in the world to setup, but after you've done it a couple of times its not too bad.