Dear all,

I have two S7 400H PN/DP stations and I need to connect them redundantly (on Ethernet) both for the failure of PLC and communication. For that I think both ports of each pair of PLC should be connected to a pair a switches and the four switches resulting from that should form a ring (in the Industrial Communication catalog (IK PI) are some examples and Scalance X408 is used).

The problem is that Scalance X408 is not available to purchase anymore and I cannot add the XM 400 series (which is the successor product) in Simatic Manager.

I tried to make this connection with X200 or X300 but without success (errors when compiling)

Any ideea how can I solve the problem?

Best regards,

h2_504

h2_504

Dear all,

I have two S7 400H PN/DP stations and I need to connect them redundantly (on Ethernet) both for the failure of PLC and communication. For that I think both ports of each pair of PLC should be connected to a pair a switches and the four switches resulting from that should form a ring (in the Industrial Communication catalog (IK PI) are some examples and Scalance X408 is used).

The problem is that Scalance X408 is not available to purchase anymore and I cannot add the XM 400 series (which is the successor product) in Simatic Manager.

I tried to make this connection with X200 or X300 but without success (errors when compiling)

Any ideea how can I solve the problem?

Best regards,

h2_504

 Can you upload your errors meassage to help solving your problem ?

Hi,

if the two PLC are not to far from each other you can work with two Scalance only.

Both left sides of each PLC to switch one and both right sides of each PLC to switch two. That is sufficient.

You also do not need this expensive and overloaded X400 switches to do that configuration.

Look at the X200 family. That will work for you. You have just to take care that one of the switches you use is capable of being ring manager RM.

Regards
Myst

Hi,

Review your design against the examples in the Configuration Examples for S7-400H with PROFINET.

h2_504

Dear all,

I have two S7 400H PN/DP stations and I need to connect them redundantly (on Ethernet) both for the failure of PLC and communication. For that I think both ports of each pair of PLC should be connected to a pair a switches and the four switches resulting from that should form a ring (in the Industrial Communication catalog (IK PI) are some examples and Scalance X408 is used).

The problem is that Scalance X408 is not available to purchase anymore and I cannot add the XM 400 series (which is the successor product) in Simatic Manager.

I tried to make this connection with X200 or X300 but without success (errors when compiling)

Any ideea how can I solve the problem?

Best regards,

h2_504

Hello, 

Could you please attach here a sketch of your network design?

You said that you need to connect the two S7-400 redundantly on Ethernet. Do you mean that you would like to make 4 redundant CPUS? !

Hi Mohamed Ali!

Sorry for the late reply, I was at a commissioning where things weren't too smooth unfortunately and I had no time for anything else.

The errors are the following:

I attached a sketch of what I am trying to do: obtain redundancy if both a CPU and a switch should fail at the same time.

Hi Myst!

Sorry for the late reply, I was at a commissioning where things weren't too smooth unfortunately and I had no time for anything else.

I thought at this, but I have two doubts:

1. What is a CPU fails and before you get the chance to change a switch also fails?

2. If a switch fails will the H system know to change to to the other CPU? In other words, how will the H system behave if the communication fails, but the H system itself is OK? Does it know to change the active CPU to the standby CPU if the communication of the active CPU fails from external causes (faulty switch)?

In the previous post I attached a configuration I thought it would solve these issues, but unfortunately it is not working.

Best regards,

h2_504

Hi Ayman!

I attached a sketch in a previous post. I am trying to connect two redundant systems S7400H through a redundant network.

Best regards,

h2_504

If the blue line you have drawn between the switches is the ring, then you will not be able to connect the cpus the way you have drawn it because then you short-circuit the network.

This is what Step7 tells you when you compile. It is not an error with the switch.

Remember that the two ports in each cpu is also a switch so when you connect both to any switch in the network without it being defined as a ring-port, any telegram sent from one port of that cpu will be received on the other port which will be incorrect.