Siemens CPU 416-2 PLC's

Dear Sirs,
I think I mis-identified which particular 416-2 PLC I am using where.

I have two 6ES7416-2XK04-0AB0, and two 6ES7-2XN05-0AB0 PLC's.

I thought I had three of the 2XK04's and one of the other . . . In reality I should have had three 2XN05's and one of the other.

The fact is, I have two of each.

Does anyone know if there should be any problem just loading the program for one into the other and expecting it to run?

The three that are supposed to be the same have the same 'RAM card' plugged into them - 2 MB RAM. (6ES7 952-1AL00-0AA). The one that is supposed to be different has a 2MB 5V Flash module (6ES7 952-1KL00-0AA).

Any insights would be appreciated.
Mad Poet.

I doubt that will work since they don't seem to be the same units. Can't you just update the hardware for the ones that you want changed?

You can just drag the -2XN05- CPU from the hardware catalog on top of the existing -2XK04- to replace it in the hardware configuration with the incorrect CPU.

Note: make sure you don't use a higher firmware version of -2XN05- than you have in the CPU.

Also take note on how to transfer the program to the FLASH:

https://support.industry.siemens.com/cs/document/23670531/how-can-you-write-the-program-to-the-flash-memory-card-when-using-a-simatic-s7-400-cpu-?dti=0&lc=en-WW

I think you should clarify what you mean by program... If you mean just the source code, e.g. the OB, DB, FB and FC, then you can use it in whatever PLC you want as long as you are not addressing memory areas that are non-existent or functions that are not supported by the CPU. Usually this is a problem between S7-300 and S7-400 CPUs but not so much between the same family.
You will have to reconfigure the hardware to match whatever is installed though, but you can right click on the CPU and choose replace and select another one.

Cardosocea> I think you should clarify what you mean by program...

Dear Sirs,
By 'Program'. . . the S7 project has the PLC's and a mechanism for reloading the PLC's. What I'm speaking of is reloading the program from the project into the PLC.

See, we have three rather large machines, one is 'small', the next is 'medium sized, and the third is 'extra large'. Other than the physical size of the machine and the fact that the bigger the machine the more drives it has in it the computers and PLC's are the same. Or at least they look the same. There was also an extra computer in a cabinet interfacing the three machines to the rest of the world, and it had the fourth of these PLC's in it.

The little machine broke bad (a common rectifier went bad and ate two 7.5 KW Masterdrives) then one of my co-workers quadrupled the problem by turning on some profibus terminators. I was called in. In troubleshooting things I swapped the PLC from the 'interface cabinet' (which we never used) with the one in the machine . . . downloaded the program into it and lo-and-behold that part seemed to work. Still had drive problems then I recognized and fixed the profibus termination problems and, finally, figured out what the original problem was. Then the Ethernet module in the PLC went bad and I think I swapped the PLC back for the original and the Ethernet card from the 'interface' and put in the spare common rectifier and the one remaining good spare drive and I was able to make some things move again.

Yesterday I was documenting what we had so the Boss can try to get some spare parts, and instead of having three PLC's of one flavor and one different, I have two of each.

The Boss also thinks I should swap the PLC back out in the little machine just to make sure it works and we do have a usable spare.

I think I know where and how to reconfigure the hardware for the different type PLC. I was looking at the specs, the 2XN05 type seems to have twice the on board memory of the 2XK04 but the total 'Load Memory' on all three machines comes in slightly less than 2 Million Bytes so I think that'll be OK.

I do appreciate any insights and opinions.
Mad Poet.

The reason for the distinction is that in the program folder you also have a file with the configuration that should be different depending on what you configured in the hardware.
This is why I highlighted the source code and not the program folder.

If the hardware is configured correctly and your code fits within the available space you are good to go. I would even risk saying that some CPU's may even work with other settings, but wouldn't bother trying that if you have access to the tools to do the right job.

Dear Cardosocea,

This just keeps getting better.
I went down to the three machines and checked the hardware configuration versus what was physically present. The big machine both the hardware configuration and the physical processor are 2XN05. The medium sized machine both are 2XK04's.

The little machine the hardware configuration thinks it has a 2XK04, while the physical processor is a 2XN05. And the machine is running production. (The bad drives and rectifier were repaired then reinstalled.)

I'm reviewing my notes on checking the memory usage, and I think it says 'Size in Load Memory' - is what must fit in the plug in memory module. And the 'size in work memory' is what has to fit in the CPU's main memory. The three machines have two MB plug in modules - and the biggest machine uses almost 1.9 MB. On all three machines the total 'Size in work memory' is 837,022 to 837,142 bytes.

I agree that I should fix the hardware configuration . . . I no longer see any problems in swapping the PLC's around.
Thanks.
Mad Poet.

If the "lesser" CPU is compatible with the "greater" CPU, then you can have the "lesser" CPU in your hardware configuration, with the real-world CPU being the "greater" CPU, and it will be fine. The catch is that you can't use more memory or use any additional features or benefits of the "greater" CPU.

Mad_Poet said:

Dear Cardosocea,

This just keeps getting better.
I went down to the three machines and checked the hardware configuration versus what was physically present. The big machine both the hardware configuration and the physical processor are 2XN05. The medium sized machine both are 2XK04's.

The little machine the hardware configuration thinks it has a 2XK04, while the physical processor is a 2XN05. And the machine is running production. (The bad drives and rectifier were repaired then reinstalled.)

I'm reviewing my notes on checking the memory usage, and I think it says 'Size in Load Memory' - is what must fit in the plug in memory module. And the 'size in work memory' is what has to fit in the CPU's main memory. The three machines have two MB plug in modules - and the biggest machine uses almost 1.9 MB. On all three machines the total 'Size in work memory' is 837,022 to 837,142 bytes.

I agree that I should fix the hardware configuration . . . I no longer see any problems in swapping the PLC's around.
Thanks.
Mad Poet.

Click to expand...

Like I said previously, there's a good chance that they would work with the wrong settings, but if the job can be done right...

Out of curiosity . . .

Does anyone know if a "6ES74162XP070AB0" will work as a direct replacement for the PLC's I currently am using?

(My boss has a quote listing it as a successor.)
Mad Poet.

Yes.

https://support.industry.siemens.co...rom-one-s7-400-cpu-to-another-?dti=0&lc=en-WW

Dear SigmaDelta,
All too often folks fail to say 'Thanks'.

Thank You.
(No reply necessary.)

MadPoet.