I am wondering, what is the most reliable way of sharing data between a “Master” PLC and a number of “slave” PLC´s?

I have used GET/PUT but I only managed to create a point to point communication.

I have also used DataSync which builds on TSEND_C / TRCV_C Which I got from her:https://support.industry.siemens.com/cs/document/39040038/data-synchronization-over-open-communication-between-multiple-field-devices-(s7-1200)-and-a-head-plc-(s7-1200-s7-300-winac)-(set-17)-?dti=0&lc=en-WW

DataSync works fine but it is freezing on me. The Head PLC can freeze if one of the Field PLCs are turned off or if I download to one of them. Then I need to restart the Head PLC to get the communication going again. The problem with that is that the Head PLC in that certain factory can only by reset then there is no production, which is rarely.

Nr_of_Substations is 3

Act_SubStation is 1

REQ_1 is stuck on TRUE.

Sub_01 state is 2 and Sub_02 and Sub_03 is 3.

In the first TSEND_Instance REQ is TRUE and Status is 7000

So is there a better and more important a more reliable way to send between two PLCs?

Or does anyone have a suggestion on how to reset the DataSync without having to reset the Head PLC without sending zero to other field PLCs?

HannAri

...

I have used GET/PUT but I only managed to create a point to point communication.

...

Does anyone have a GET/PUT sample code with multiple client’s?

In att. is how I am thinking about doing it. Does someone have a better suggestion?

OK, after reading more on the GET/PUT instruction then the I got it to work and it seems to be much more stable and easier to use than the DataSync instruction. So I think I have solved this problem on my own. 

Hello,

I used the dayasync example, and I faced the freeze problem, and finally I have solved it.

the problem was, if the Ethernet connection is interrupted between master and slave devices the connection didn't get online again unless I do stop/run master CPU, I have checked online during the problem and I see the #step value is stopped at 22.

I have modified the FB "FB_EthernetCommunication_HEAD" for the master CPU as follows:

1- I created a new BOOL value called "TRcv_Alarm"

2- I created a new TON_TIME  called "IEC_Timer_1_instance"

at the code I have added the following code:

#IEC_Timer_1_instance(IN := #TRcv_Busy,
PT := t#6s,
Q => #TRcv_Alarm);

I have updated the code at #step 22 as follows (copy the old and new code):

22:
IF #TRCVDONE THEN
#Step := 23;

ELSE
IF #TRcv_Error THEN
#Step := 40;
ELSE
IF #TRcv_Alarm THEN
#Step := 40;
END_IF;
END_IF;
END_IF;

I have tested the new modification for one week, and it is working fine for me.

if the Ethernet connection is interrupted, the connection is returned online successfully.