Siemens software and software / hardware redundant systems

Hello All

I didn’t work with redundant systems before, really need to know what is the main difference between software redundancy; and software / hardware redundancy?

Is both of them working with 2CPUs carrying each other as a hardware and software; what makes me select s7 400H instead of S7 300/400?

I have a project in water application; required to build a redundant system for that application; Client is requiring software and hardware redundancy; however trying to convince that such application enough to operate with software redundancy.

I’ve proposed the system containing below:-

1. 2 Nos CPUs (CPU 315-2 PN/DP)
2. ET200M IOs including (IM 153-4 for ET 200M, PROFINET) + digital and analog IOS

Can this system work as a redundant with profinet network

Thanks in advance

 Hello Abdullh;

Abdullah Maher

I have a project in water application; required to build a redundant system for that application; Client is requiring software and hardware redundancy; however trying to convince that such application enough to operate with software redundancy.

I’ve proposed the system containing below:-

1. 2 Nos CPUs (CPU 315-2 PN/DP)
2. ET200M IOs including (IM 153-4 for ET 200M, PROFINET) + digital and analog IOS

Can this system work as a redundant with profinet network

Thanks in advance

 You are asking us for the differences between Software Redundancy (SWR) and H-Syatems, but you are ready to tell the client that his application can work without problem with SWR? What calculations do you base your decision on?

SWR might be a valid solution for your client. Then again, it might not be. You must evaluate the capaities and pricing of each system and the client requirements carefully before proposing a solution.

Please take note that:

- SWR may take up to 1 sec. to switch over from Primary to Standby CPU (depending on the network connection you choose for the project), while the S7-400H is virtually bumpless (switch in msec). That is because the connection between Primary and standby is through dedicated fiber-optic cables, and the runtime of both CPUs is always active in parallel (in redundant mode) so there is no time lost for the standby to take over the duties of Primary.

- SWR does not allow redundancy on the level of I/O, whereas H-Systems does allow redundant DIs , DOs and AIs, voting, and other configurations.

- SWR will cost a lot les but will not provide the topologies, reaction time and security of H-Systems. And you will have a lot more programming required to setup and maintain the SWR.

Again, please evaluate carefully the requirements of the client's project before you choose one system over the other.and proposing a solution that fits his specified needs. See the following discussion from the forum for more details.

software and hardware redundancy in siemens

As far a using Profinet I/O with SWR, this is not allowed.

See these links:

S7-300 REDUNDANCY USING PROFINET

S7-300R system

Hope this helps,

Daniel Chartier

New question published by AutoGen_3451117 is split to a separate thread with the subject Redundant systems: Siemens and ifm.

Best regards
Jen_Moderator