SIMATIC S7-400 / S7-400H / S7-400F /FH
CPU417-4H Multi tasking with 2 CPU (Load sharing of single redundant CPU)
Thread Starter: chetan747 Started: 7/13/2012 12:17 PM Replies: 9
7/13/2012, 12:17 PM
|
Joined 3/13/2008
Last visit: 4/27/2013
Posts: 14
Rating:
![Rated: no ratings [0 out of 5 / rated 0 time(s)].](/forum/Skins/images/Star0.user.gif) (0)
|
![Rated: no ratings [0 out of 5 / rated 0 time(s)].](/forum/Skins/images/Star0.post.gif) (0)
|
Dear All,
Any one have idea about program spliting in CPU417-4H redundant configuration with two seperate CPU417-4H redundant set. I have a CPU with maximum load and I have add some more control in the same but it is not possible with existing running load. I read somewhere in the CPU manual that it is possible to share the load with two seperate controller with multitasking computing to reduce the load.
waiting for your valuable suggestions.
Regards,
=== Edited by chetan747 @ 7/13/2012 12:18 PM [GMT ] ===
|
|
|
|
|
7/13/2012, 3:30 PM
|
Joined 9/27/2006
Last visit: 5/22/2013
Posts: 3941
Rating:
![Rated: Excellent [4.15 out of 5 / rated 619 time(s)].](/forum/Skins/images/Star4Half.user.gif) (619)
|
|
(0)
|
Hello chetan;
It seems that multicomputing is not supported by S7-400H systems.
As shown in the SIMATIC Fault-tolerant systems S7-400H manual:
Restrictions of the fault-tolerant CPU compared to a standard CPU
Function Restriction of the fault-tolerant CPU
Hot restart A hot restart is not possible. OB 101 is not possible
Multicomputing Multicomputing is not possible. OB 60 and SFC 35 are not supported
Startup without configuration loaded Startup without loaded configuration is not possible.
...
Could you give any indication on the load supported at this time by your S7-417H, and the additionnal load you plan to integrate? The S7-417H is a monster of a PLC and it takes quite a process to fill it up.
In my experience, when we have faced such issues (it happened in an alunimium plant we programmed with PCS 7, all OB3x were at their limit) we had to setup another redundant controller pair to split the control area into sections that we distributed through multiple controllers.
Hope this helps,
Daniel Chartier
=== Edited by dchartier @ 7/13/2012 10:57 PM [GMT ] ===
|
|
|
|
|
7/14/2012, 8:12 AM
|
Joined 3/13/2008
Last visit: 4/27/2013
Posts: 14
Rating:
(0)
|
|
(0)
|
Dear Daniel,
Thanks for the reply. Presently my memory load is as following.
Load Memory RAM: 85%
Work Memory code: 63%
Work Memory Data: 21%
Now I have some more extension of program with the spare IO connected on the same CPU. I have 20% spare IO with this CPU which I cant utilise with by extending new program due to memory load.
If you have any experiance of set up additional CPU with existing CPU to reduce load of existing one, then please guide me how to do it.
Regards,
Chetan
|
|
|
|
9/28/2012, 11:25 AM
|
Joined 3/2/2007
Last visit: 5/21/2013
Posts: 150
Rating:
![Rated: Outstanding [4 out of 5 / rated 1 time(s)].](/forum/Skins/images/Star4.user.gif) (1)
|
|
(0)
|
kindly , how did you solve this problem ? thank you
|
|
|
|
9/28/2012, 5:52 PM
|
Joined 3/13/2008
Last visit: 4/27/2013
Posts: 14
Rating:
(0)
|
|
(0)
|
Still I am waiting for solution. This problem is still un resolved.
|
|
|
|
9/29/2012, 7:19 PM
|
Joined 9/27/2006
Last visit: 5/22/2013
Posts: 3941
Rating:
(619)
|
|
(0)
|
In my experience, when we have faced such issues ... we had to setup another redundant controller pair to split the control area into sections that we distributed through multiple controllers.
Hello Chetan;
I hope you don't have to wait much longer for a solution...
Seriously, if you have reached the end of the work memory of a S7-417H CPU, you must be controlling a large and complex process. The newer S7-417H CPUs have 30 MB work memory, and the work memory cannot be expanded. There are no CPUs more powerful in the S7 family.
Please give us at least the MLFB of your CPUs, to see if an upgrade to a newer version could increase the available work memory. But even that would be an expensive workaround, and might just be a stopgap solution..
So if you really have no other choice, as I said you have to take a step back, analyse the process you are controlling, split it into logical sections that you will split between 2 CPus, making sure that you have planned data exchanges between the seperate redundant controllers for alarm reaction and interlocks.
Then determine if certain sections do not require redundant control; if they do, evaluate how large the new redundant CPUs must be (can the load be taken by a redundant CPU 414H, for example) and plan your new setup .
Regards,
Daniel Chartier
=== Edited by dchartier @ 9/29/2012 10:57 PM [GMT ] ===
=== Edited by dchartier @ 9/29/2012 8:01 PM [GMT ] ===
|
|
|
|
|
|
Thank you for this post from:
|
10/4/2012, 1:54 PM
|
Joined 10/31/2005
Last visit: 5/22/2013
Posts: 2092
Rating:
(200)
|
|
(0)
|
Well, Daniel is absolutely right in case if reached work memory limit. If you reached load memory limit you can just buy larger RAM card and insert it into CPUs. Please clarify what memory in not sufficient - it's not clear to me.
|
|
|
|
|
Thank you for this post from:
|
10/19/2012, 10:10 AM
|
Joined 3/13/2008
Last visit: 4/27/2013
Posts: 14
Rating:
(0)
|
|
(0)
|
Thanks all for your valuable suggestion. I will go with your suggestion and will procure higher size Memory card. And check the same.
|
|
|
|
10/19/2012, 10:15 AM
|
Joined 3/13/2008
Last visit: 4/27/2013
Posts: 14
Rating:
(0)
|
|
(0)
|
Dear dchartier,
Kindly find the CPU MLFB of our CPU range.
MLFB: 6ES7656-8EM32-3CX0
I will go with the idea of increase the memory of the CPU and revert back with new data.
Regards,
|
|
|
|
10/19/2012, 6:11 PM
|
Joined 9/27/2006
Last visit: 5/22/2013
Posts: 3941
Rating:
(619)
|
|
(0)
|
Hello chetan;
Unfortunately, the MLFB you have shown is the part number fpr a S7-417H bundle purchase.
Could you please read-off the MLFB from the CPU directly, for example:
6ES7417-4HT14-0AB0
Open the link above to see technical information on that CPU model.
Hope this helps,
Daniel Chartier
|
|
|
|
Actions
Print