SIEMENS PLC to PLC communication failure between S7 300 and S7 400 systems.

We have HRSG with its diverter system. HRSG has S7 417H-4HL01-0AB0 V3.1.4 and Diverter has S7 314-6BG03-0AB0 V2.6.11 CPUs. They communicate each other through Plant Bus. PLC to PLC communication between HRSG and Diverter PLCs was fine. Recently we purchased one PLC and one CP for S7 300 system for Diverter (same model and version). To test and check, first we replaced old running and good PLC with the new one (old memory card was used). Everything was fine. All the commands from Central control room HMI to diverter system were working.

But when we tried to replace (diverter S7 300) CP 343-1EX11-1XE0 V2.2 we used new MAC address and put in the SIMATIC Manager (5.3+H.F4) H/W configuration. When we compile H/W configuration editor, it changes MAC address in “netpro” of both PLCs (S7 300 and 400). After downloading, local diverter PLC, local system runs fine but it loses PLC to PLC communication between diverter and HRSG. No command works from remote control room HMIs. I thought that as the MAC address was changed at diverter end, that’s why I downloaded “netpro” to HRSG (S7 400 PLC). But no change was observed.

Note: S7 400H system CP: 443-1EX11-0XE0 V2.4

Note: S7 300 system CP: 343-1EX11-1XE0 V2.2

Again I put original MAC address (commissioning period address) in diverter and HRSG. Downloaded diverter project in Diverter CPU and HRSG project in HRSG CPU but still no change in the communication. Please note that all the command tags and feedback tags (of diverter) in the HMI screen are assigned in HRSG controller getting through the PLC to PLC communication from diverter CPU. At this moment I have no idea to solve the communication problem. I did the same thing back on 2011 but no issue provoked then. Please help me to solve this issue.
 

Attachments

We have HRSG with its diverter system. HRSG has S7 417H-4HL01-0AB0 V3.1.4 and Diverter has S7 314-6BG03-0AB0 V2.6.11 CPUs. They communicate each other through Plant Bus. PLC to PLC communication between HRSG and Diverter PLCs was fine. Recently we purchased one PLC and one CP for S7 300 system for Diverter (same model and version). To test and check, first we replaced old running and good PLC with the new one (old memory card was used). Everything was fine. All the commands from Central control room HMI to diverter system were working.

But when we tried to replace (diverter S7 300) CP 343-1EX11-1XE0 V2.2 we used new MAC address and put in the SIMATIC Manager (5.3+H.F4) H/W configuration. When we compile H/W configuration editor, it changes MAC address in “netpro” of both PLCs (S7 300 and 400). After downloading, local diverter PLC, local system runs fine but it loses PLC to PLC communication between diverter and HRSG. No command works from remote control room HMIs. I thought that as the MAC address was changed at diverter end, that’s why I downloaded “netpro” to HRSG (S7 400 PLC). But no change was observed.

Note: S7 400H system CP: 443-1EX11-0XE0 V2.4

Note: S7 300 system CP: 343-1EX11-1XE0 V2.2

Again I put original MAC address (commissioning period address) in diverter and HRSG. Downloaded diverter project in Diverter CPU and HRSG project in HRSG CPU but still no change in the communication. Please note that all the command tags and feedback tags (of diverter) in the HMI screen are assigned in HRSG controller getting through the PLC to PLC communication from diverter CPU. At this moment I have no idea to solve the communication problem. I did the same thing back on 2011 but no issue provoked then. Please help me to solve this issue.
Hello,
Please first desribe the communication configuration used: is one of the CPUs the Profibus master, the other one the slave, and how are the data exchanges configured?

ControlsGuy25.
 
Today I downloaded single project to Diverter PLC and multiproject to HRSG PLC but no change. Please see the drawing below.


Protocol.jpg
I couldn't find any mismatch on both side CP Mac Address.:cry:
Each HRSG has redundant PLCs with master and slave configuration and diverter has single PLC connected through plant bus industrial ethernet. Profibus DP is used to connect IO system and field devices for HRSGs. I have attached a pdf of our dcs network. Please ignore Diverter 1-4 connected to terminal bus as per pdf but physically diverters are connected to Plant bus.
 

Attachments

Today I downloaded single project to Diverter PLC and multiproject to HRSG PLC but no change. Please see the drawing below.


View attachment 661
I couldn't find any mismatch on both side CP Mac Address.:cry:
Each HRSG has redundant PLCs with master and slave configuration and diverter has single PLC connected through plant bus industrial ethernet. Profibus DP is used to connect IO system and field devices for HRSGs. I have attached a pdf of our dcs network. Please ignore Diverter 1-4 connected to terminal bus as per pdf but physically diverters are connected to Plant bus.
Good day,

Thanks for sharing DCS/controls systems architecture ...

I know this plant , it is a GE Belfort project...I know very well the team who did commissioning on this plant.

Would you tell us :
-When problem started /occured...
-Did you get over OB 87 error code as it explained on OEM manual for such "Communication error"
In th first File that you *shared, it is Displayed "OB34" ( Manual saying that it is an cyclic alarm.)
-Would you also tell us what protocol/cionfiguration /procedure /programming did you set for getting the communication configured

There are many links on Siemens Portal , you can try to have a search on this web site

Here is one of these link on how to configurate Comm with S7400:
https://support.industry.siemens.co...fb15-(-put-)-with-s7-400?dti=0&dl=en&lc=de-WW

Do not hesitate to give your feedback...

Controls Guy25.
 
we used new MAC address and put in the SIMATIC Manager (5.3+H.F4) H/W configuration
First mistake!!!
Again I put original MAC address (commissioning period address) in diverter and HRSG.
Second mistake!!

Layer 2 networking depends on ARP configurations. This is why some find this troublesome.
Layer 2 networking is secure!!!! but sometimes hard to understand.

The post has some information but not enough to troubleshoot MAC address resolution issues.
 
Hello Controls Guy25

Thanks for your query.

-When problem started /occured... (I wanted to replace CP 343 and downloaded diverter project with device mac address (printed one) and from then the communication problem started)
-Did you get over OB 87 error code as it explained on OEM manual for such "Communication error" (I don't know where to find OB 87
In th first File that you *shared, it is Displayed "OB34" ( Manual saying that it is an cyclic alarm.) (There is no alarm on other HRSG to diverter communication block)
-Would you also tell us what protocol/cionfiguration /procedure /programming did you set for getting the communication configured (industrial ethernet, please take a look the attached pictures for your better understanding)
 

Attachments

Thanks Curious_One

we used new MAC address and put in the SIMATIC Manager (5.3+H.F4) H/W configuration
First mistake!!! Whatever address I use, if both end Local and partner is same then it should work unless I change Send and receive configuration.
Again I put original MAC address (commissioning period address) in diverter and HRSG.
Second mistake!! I wanted to revert by putting original address. I just downloaded complete diverter project but no change. Even I used IP address instead of MAC but same.

Layer 2 networking depends on ARP configurations. This is why some find this troublesome. It would be better if you give a brief on ARP configurations.

Thanks again.
 
Hello Controls Guy25

Thanks for your query.

-When problem started /occured... (I wanted to replace CP 343 and downloaded diverter project with device mac address (printed one) and from then the communication problem started)
-Did you get over OB 87 error code as it explained on OEM manual for such "Communication error" (I don't know where to find OB 87
In th first File that you *shared, it is Displayed "OB34" ( Manual saying that it is an cyclic alarm.) (There is no alarm on other HRSG to diverter communication block)
-Would you also tell us what protocol/cionfiguration /procedure /programming did you set for getting the communication configured (industrial ethernet, please take a look the attached pictures for your better understanding)
Hello SaberMPS,

Thanks for your feedback!

I had a look on the shared files, my question is :

-Wich procedure did you follow for replacing that CP343?

Did you have a look on youtube videos concerning S7 communication configuration...

Here is one of these interesting video...you can see that SF15 is used for such operation...:

Also you stated that FB14 is not same as OEM manual... that can be an issue to solve too...

My advise is alos to catch that OB87 and see what you got from it...then you can do a better troubleshooting..

I know Bangladesh well, We commissionned that Tongi Plant at suburban of Dhaka/Dacca...

I hope that it helps,
ControlsGuy25
 
Layer 2 networking depends on ARP configurations. This is why some find this troublesome. It would be better if you give a brief on ARP configurations.

https://study-ccna.com/arp/
That is just a little info. Try typing in arp -a from a command prompt. I think you will find that the IP address and the MAC address does not match your configuration. Your software attempts to make the relationship between static ip address and MAC address.

When the machines try to communicate they form a dynamic relationship because ARP (Address Resolution Protocol) does just that. I believe something is amiss in your configuration. Using arp tables might help resolve it.
 
Here is a example:
I have some software on device 1 that requires a static relationship between ip address and mac address.
I configure the following:
device 1 to 192.168.1.95 8C-EC-4B-86-05-26
device 2 to 192.168.1.101 b8-27-eb-ca-69-3c
device 3 to 192.168.1.102 b8-27-eb-3c-69-7e

Now I need to check the network comms for these devices
I go to the command prompt on device 1 and type in ipconfig /all and find that device 1 setting are correct.
Now I type in arp -a and find the arp table empty.
I decide to check communication to device 2 and type in ping 192.168.1.101
reply
Pinging 192.168.1.101 with 32 bytes of data:
Reply from 192.168.1.101: bytes=32 time<1ms TTL=64
Reply from 192.168.1.101: bytes=32 time<1ms TTL=64
Reply from 192.168.1.101: bytes=32 time<1ms TTL=64
Reply from 192.168.1.101: bytes=32 time<1ms TTL=64

Ping statistics for 192.168.1.101:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

192.168.1.101 responded so that means the arp table is populated dynamically.
I type in arp -a and find that 192.168.1.101 is at b8-27-eb-3c-69-7e when it should be at b8-27-eb-ca-69-3c
I simply made a mistake in my static configuration of device 2 and 3.

Hope this helps.
 
Thanks ControlsGuy25 for your support and time for me.

When I open DB126 (inst_db_recv) the offline actual value shows ID_0=W#16#4A and ID_1=W#16#4B. When I go online of the same block it shows actual value ID_0=W#16#003A and ID_1=W#16#003B.Why??? I tried to change it to W#16#004A and W#16#003B but doesn’t work (please see the attachments). Is wrong assigned ID causing the problem?

Local and partner Id configured in netpro for our 4 diverters in the following manner:

Unit nameLocal ID (diverter)Partner ID (HRSG)
Diverter11​
1A1A
1B1B
1C1C
1D1D
Diverter 21​
2A2A
2B2B
2C2C
2D2D
Diverter12​
3A3A
3B3B
3C3C
3D3D
Diverter22​
4A4A
4B4B
4C4C
4D4D


I don’t see OBs, FBs etc in offline mode of block folder. But in online block folder I can find OB1, OB100 but these are not same as what I see sample programfor OB1 in SIEMENS portal and the video that you shared.

The answer of your question:

Which procedure did you follow for replacing that CP343?

Explaining step by step:

1. Switched off the power supply of the CP

2. Replaced the CP with a new one

3. Used latest multiproject (Step 7 V6.0) to download Diverter22 SIMATIC314. Used factory mac address from the device and changed it HW configuration. Used Simatic PG to download.

4. Used Ethernet port of the CP to download the program. after that S7 communication lost.

5. Again downloaded from ES with new MAC, no change.

6. Again Downloaded from PG directly to CPU using MPI-USB connector with SIMENS provided mac, no change.

I think S7 communication failure is happening from Local and Partner ID missmatch. It should be 4A and 4B but online shows 3A and 3B. But unfortunately I can’t change it.
 

Attachments

Sorry for the above table:

Local and partner Id configured in netpro for our 4 diverters in the following manner:

Diverter11 Local ID and Partner ID for S7 connection is 1A, 1B, 1C, 1D

Diverter21 Local ID and Partner ID for S7 connection is 2A, 2B, 2C, 2D

Diverter12 Local ID and Partner ID for S7 connection is 3A, 3B, 3C, 3D

Diverter22 Local ID and Partner ID for S7 connection is 4A, 4B, 4C, 4D
 
Sorry for the above table:

Local and partner Id configured in netpro for our 4 diverters in the following manner:

Diverter11 Local ID and Partner ID for S7 connection is 1A, 1B, 1C, 1D

Diverter21 Local ID and Partner ID for S7 connection is 2A, 2B, 2C, 2D

Diverter12 Local ID and Partner ID for S7 connection is 3A, 3B, 3C, 3D

Diverter22 Local ID and Partner ID for S7 connection is 4A, 4B, 4C, 4D
Hi SaberMPS,

Thank you for your Message&feedback! it is greatly appreciated..

Did you have use that following tool for better Diagnostic &troubleshooting :
https://support.industry.siemens.co...-and-profinet-io-(step-7-v5-x)?dti=0&lc=en-WW

I will have a better review on the files that you shared...I definitely advise you to search why FB14 is not same as OEM Manual description...

Also can you devellop on that OB34 ..as i see OB87 should be also giving you more datas on what is wrong I think.

One question :

Do the designed PLC got its own HMI /Touch panel whatever it is called...and if yes how about PLC/HMI communication configuration ..I mean is the comm operating smoothly..
As I am not at your site , there can be many questions to ask, but it is difficult to answer remotely...

Lets see if somebody here can add more on this thread..

I am sure that can help !

ControlsGuy25.
 
Hello all...
You can override the default FB with your own customized version...this could account for why they are not the same as the OEM.
....if that helps. If I remember correctly you need the offline version of that FB code.
As for PCS7 it is a difficult system to fault-find remotely there is just so much to the system...
 
Finally the system is working. The project software that used to download got the wrong IDs. Thanks everyone for sharing your thoughts.
 
Finally the system is working. The project software that used to download got the wrong IDs. Thanks everyone for sharing your thoughts.
Thanks for sharing the feedback...
Indeed This wrong IDs can be source of issue...
I was pretty sure about a mistake on the configuration.... As I wrote in my posts...

As we are not at your site...
 
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