Cimplicity controlling redundancy between 90-30 PLC's

Hello, I have the following problem:

My costumer have a system configured as follows:

- Two set`s of 90-30 controller + IO's.
- Engineering and backup station running Cimplicity version 6.0

The set's of PLC's work in a cold-stanby redundancy, and follows these rules:

Each set has it's own I/O.
Each controller has access to it's own I/O only.
The process of switching is controlled by Cimplicity.

And we have the following problem: The redundancy control in the Cimplicity software uses a preferred PLC (primary PLC), which has the control unless it goes down. That means, if PLC A is the primary and PLC B the secondary, when we get PLC A down, the control is set (by Cimplicity) to the PLC B. But when we fix PLC A problem and put it on line again, the Cimplicity automatically set it to the controlling position.
This way, since the stand by is in cold mode (that means, each time it changes, we have many data to be restored from Cimplicity and from a Oracle database, prior to the start of control), when we have a shutdown in PLC A, we have to loose time while switching to PLC B, and loose time again, when PLC A is set back.

I have suggested the costumer to buy the MAX-ON sulution, but they will not.

So, there's anything to do about this in Cimplicity? Any way to configure it to have a dinamically assigned primary PLC?
Thanks in advance,
Valter Carvalho

You made it right - offered MAXON to the customer. Customer's requirements would be fulfilled by MAXON and also CIMPLICITY is managing this well. If your customer wants to save money in purchasing he will spend a multiple for the handicrafted solution. Who should maintain this?

Yes, that's the point, I'm sure MAX-ON will be the best solution, but the costumer is a bit hard-minded, it is difficult to present new ideas to them.
But, I would like to have answer to 2 major questions:

1) What is the time of switching between primary and secondary PLC in case of failure, using MAX-ON? We have a hump yard process that shoul not be stopped in case of failure in one PLC.

2) What is the overhead in processors due to the use of MAX-ON? Is it significant? Also, we have a program that is scan-critical, so any overhead in processor should be considered.

3) And, finally, in case of using only Cimplicity instead of MAX-ON, there's any way of configure it to hava a float master, i.e., to change the mastership to the processing PLC, not to have is static on only one PLC?

Any help will be much appreciated!

I can not answer your questions without a fair amount of research of which I do not have time for right now.
However if you are using Proficy ME and have Modern CPU's like the CPU360 or 370 family, performance should not be a problem. If you have CPU331 it could be.
In any case you may be able to use a 'C' Block to monitor and update a couple of registers in each PLC for Cimplicty HMI to work with. However developing this just may cost as much as Max-On.

Valter,
After your explanations it seems to be a critical process! MAXON is a "warm" standby system. Master and slave CPU exchange data in a constant period which is not related to the scan. Depending on the communication interface (Genius/Ethernet) it takes more or less. TUV approved controllers for critical control (Hot Standby with bumpless switching) are based on special CGR controllers based on 90-70 platform. Absolut different pricing. Your customer should have a SIL specification which describes the needs in detail. But for such application you should contact your local GE Fanuc office.
Another super fast data synchronization is possible with the reflective memory technology (RX7i). It exchanges memory content within microseconds.

Mammoth has a good point, as a cost savings the RX3i platform now has "Reflective Memory" available.

Ok, so the RX3i also has the reflective memory? The RX3i is based on 90-30 I/O and can be implemmented on them? I will only have to buy the Rx3i CPU's?
Also, if I don't use MAX-ON, and use Cimplicity, it is mandatory to have a preferred master (primary), so everytime it goes up in the system, the control is automatically switched to it (even if the secondary is up and running)?
Very thank you for the supplied answers!

RX3i is compatible with the most I/O modules. You'll need only RX3i chassis, power supply, CPU, Ethernet module and refl. mem module IC695CMX128 in both PLCs. PCMs and PBMs are different too.
The CMX module is brand new and you'll need ME 5.80
As I said, for detailed information I recommend to contact the local GE Fanuc office.

Yes, I'm already in contact with our supplier, but the answers here gave me good directions for a best talking.
Very thank you all!