Hello, everybody !

I create a project with a number of PLCs S7-1200 (8 pieces). All of them have a CPU 1214C.

They have to exchange data one to another in different combinations via Profinet interface.

There is no another possibility.

Help me pls to choose optimal communication type to exchange the data between all the PLCs.

Communication TASK :

Only CPU1...CPU5 can have data to ytransfer them to all other CPUs.

For example if some event that is monitored by CPU3 occurs, then CPU3 must send a message bit to all other CPU1, CPU2, CPU4 ... CPU8 ;

- if some event that is monitored by CPU5 occurs, then CPU5 must send a message bit to CPU1...CPU4, CP6... CPU8 ;

and so on.

Which connection type should I use to link all my CPUs ?

Could anybody share a working project for S7-1200 with the above mentioned connection, please ?

Thanks in Advance.

Hello,

I would prefer to make the exchange with the I-Device connection. This is quite easy to realize. Check the Siemens support for examples.

In the end it doesn't matter if you transfer the value as raw or as digit. You just transfer one word.

Regards

Hello Alex3110,

the suggestion from SCOT123 is the best.

Is it necessary that every PLC communicate with alll the others?

My suggestion is the follow:

• one PLC is th "master"
• all the other PLC's are an I/O-device and usethe I/O-Device- communication (S7-communication) to the "master"
• create for every data-connection a UDT and us them in a project-library
  then it's easier to address all and it's consistent if you change anything

regards
CaOd

............

Alex3110

Why are we talking about "master" and a "slave" ???

The communication will be via Industrual Ethernet  !!!  

In CPU  properties I found nothing about "master" and a "slave".

 If I-device is set up, you just create a GSDML file from each "slave" station and import them to the "master" cpu. That way all of the CPU's communicate with one partner.

To communicat between CPUs the embedded Industrial Ethernet should be used.

There is no another possibility.

The question is  EVERY of the 8 CPUs of the S7-1200 family must periodically be either a SERVER or a CLIENT.

Namely :

- if some event that is monitored by CPU1 occurs, then it must send a message bit to other CPU2 ... CPU7 ;

- if some event that is monitored by CPU2 occurs, then it must send a message bit to other CPU1, CPU3 ... CPU7;

and so on.

Is the IO-Device technology suitable for my project ?

Or the GET \ PUT  also will work ?

Also is it possible to simulate the exchange of two CPUs via Industrial Ethernet?

If so, will both of these technologies allow it ?

Could anybody share a working project for S7-1200 with the above mentioned connection, please ? 

Hello Alex3110,

we understand that you want to use a Ethernet communication.

If you want to use the I/O-device then you have a "master" and all the other PLC's are "slaves".

You can also use PUT/GET but then you must use not optimized DB at all the PLC's.
This is not recommended for the 1200.

You can also use a the function T_SEND and T_RCV.

Otherwise can you also communicate via Modbus and use MB_Server and MB_Client.

In my opinion is the best way you use one PLC as a relay-station.
One reason is when eg. PLC6 must send the same value to PLC 3,5,8,9,11.
then it's easier to send this value to PLC1 (as "master") and this PLC ranks the data to hte target PLC's. 
You have not so a lot of traffic when you have a central "relay-station).

Please look at this document - CPU-CPU Communication with SIMATIC Controllers

regards
CaOd

CaOd

In my opinion is the best way you use one PLC as a relay-station.
One reason is when eg. PLC6 must send the same value to PLC 3,5,8,9,11.
then it's easier to send this value to PLC1 (as "master") and this PLC ranks the data to hte target PLC's. 
You have not so a lot of traffic when you have a central "relay-station).

......

 Not bad idea, but what to do if "master" is unreachable (cable is broken, bad connection in a socket, PLC-master power supply unit has failure , etc.). Then all the data exchange is terminated 

Alex3110

Not bad idea, but what to do if "master" is unreachable (cable is broken, bad connection in a socket, PLC-master power supply unit has failure , etc.). Then all the data exchange is terminated 

Find a design that will declare another PLC as Master if no link is found after a while.

UDP Broadcasting may offer another option. When you find a control idea to rotate the "master" token, then you can use the example:

Master-Slave Communication via UDP Broadcast