Siemens 400H, Intouch HMI.

Hi,

I have a system who is built up with 400H and Intouch HMI (two IO servers, two physical computers).
I have some problem with the redundancy, if I`m diconnect the ethernet cable on master CPU intouch switch over and start pooling data from the other CPU on the 400H system, but the challenge is if I set the CPU to stop then the intouch dont switch over...

Summary:
Intouch don`t detect that the CPU is in STOP...

Somebody have any articles etc, how to configurate Intouch the right way when its communite with a 400H system?

What do you mean by "set the CPU to stop" ?

kire said:

Somebody have any articles etc, how to configurate Intouch the right way when its communite with a 400H system?

Click to expand...

Aside from asking why the CPU is being stopped...

You might be able to do this via some form of scripting on a data change event where you are monitoring some form of boolean tag as a heart beat. Something where InTouch sets a bit, but the PLC resets it. So if the PLC doesn't reset it after some period, trigger the script to manually changeover the IO server. Might take some magic to make it reliable, and no I don't have code examples but I've done similar IO server swaps via scripting, just not triggered by a CPU stop.

rankhornjp said:

What do you mean by "set the CPU to stop" ?

Click to expand...

Stop cycle, simulate CPU fault.
These is a important system to keep up and running, only reason we are using 400H...

Paully's5.0 said:

Aside from asking why the CPU is being stopped...

You might be able to do this via some form of scripting on a data change event where you are monitoring some form of boolean tag as a heart beat. Something where InTouch sets a bit, but the PLC resets it. So if the PLC doesn't reset it after some period, trigger the script to manually changeover the IO server. Might take some magic to make it reliable, and no I don't have code examples but I've done similar IO server swaps via scripting, just not triggered by a CPU stop.

Click to expand...

Same reason as Siemens selling 400H
Critical system who must not go down...

So we simulate fault on the CPU by set the switch to stop.

Thank you for your feedback, I just wanted to make sure that Intouch dosent had any inbuild function for these against 400H,
before I start making my own script.

So I will make a script working like a roller counter, and if the counter stop then shall it switch.
What command / function shall be used in Intouch to switch I/O server?

kire said:

What command / function shall be used in Intouch to switch I/O server?

Click to expand...

IOForceFailover("AccessName")


Does the Siemens 400H have system bits? I know that the Modicon PLCs we use have a system bit that is set to "0" anytime the PLC is not in RUN.

rankhornjp said:

Does the Siemens 400H have system bits? I know that the Modicon PLCs we use have a system bit that is set to "0" anytime the PLC is not in RUN.

Click to expand...

A dirty trick is to check if the clockmemory is still changing.

rankhornjp said:

IOForceFailover("AccessName")


Does the Siemens 400H have system bits? I know that the Modicon PLCs we use have a system bit that is set to "0" anytime the PLC is not in RUN.

Click to expand...

You can read out the status of the H-system by reading out the relevant system status list (SSL). SSL id 0x71 should do the job.

You can read the data from the PLC program with SFC51, and from remote via standard S7 communication.

Only reading the status from the plc program is not enough, as if the CPU is in stop mode, also the SFC call is not processed.

Some time ago we have programmed such thing in WinCC where it was not neccessary to have a switch over in milliseconds. If you need this, WinCC has a special package for this (Redconnect).

We have programmed two things:
Read out the current master CPU from PLC program using SFC51, and in WinCC read out the status bits from both CPUs. If both CPU are in RUN, then by default connect to the current master CPU.
And second we have used a livebit counter. If one counter stops and the other is still running, then switch over to the other CPU.

Thank you all for your feedback, we are up and running with full redunc. now

Thank you.