why I have to use Memory Card on some CPU200 units while I don't use on others

Hello Experts,

I have a question about usage of Memory Card on CPU226 (and maybe others)

We have alot of CPU200's on site and some of them works with Memory Card fitted on them and some Not.

I Know that Memory card usage depends on the size of the program and also how we save parameters and so on ...

I attached 2 project that one of them with Memory Card and the other one without Memory Card, project size for the one without Memory card is bigger than the other one and also we are not saving anything permanent on Memory Card and the structure of the projects are very similar!

I can turn the power OFF-ON on the one without Memory card and project works as usual but on the one with Memory Card (fitted from start by the programmer), I can do the same if Memory Card is in its slot but if I pull out the Memory Card and then power it up the system won't work and this is the question I have " Why it doesn't work without Memory Card " 

The only different I see now is the Version of the PLC's, With Memory is Version 1.02 and without Memory is Version 2.01

Is That could be the reason for Memory Card???

Thanks

There are 2 attachment, one here and one after this 

Belong to previous comment

Both attachment work OK but for different machines.

Thanks

Hello,

for this time only one, both projects have both CPUs version 226 02.01, can you pls post info about your discovered 01. version? When I look to prj with memory card, System Block for Retentive Ranges, MB offset is from 14, but maybe your some statuses are below this offset, maybe this is unimportant. Check that retentive areas with your defined memory, maybe some important areas after power off are lost.

Hi Duris_I,

Thank you for the reply,

Download it again and check it, (just for 2 minutes I put the wrong project and then correct it with the right one).

I attached where the Version 1.02 was taken

Also there no parameters needs to be saved or backed up, when we turn it OFF - ON system starts from scratch and nothing from previous Batch will be used. 

Retentive Ranges are Factory Default on the project with Memory Card.

Thank you 

Hi William,

Thank you for the reply, I understand what you mentioned but this one is 226 and not 21x, And also as I said it is Memory Card and not Backup battery or Real Time...

Also about saving parameters on the Memory card, as you can see in the program there are no parameters saving and when ever we turn the power OFF - ON the system starts from main screen and nothing will be backed up (is a very small system for each Scale).

By what you said and what I get from Manual, they don't need a memory Card on those systems but in reality when ever I make some Online modification and download it to the PLC, system accept changes and work right but when I turn the power OFF - ON the system download the old program from Memory Card and go back to original version! then I have to Download the program again and this time I have to download the program to the Memory Card as well.

My problem starts from here that if I take the Memory Card Out and start the PLC, machine won't work without Memory Card!!! and this is where I get confused.

As I said before I have used CPU226 before and I never used Memory Card (because didn't need backup) and they've worked OK but on some of old machines we have here they have Memory Card and won't work without them.

Thank you very much by being patient to read my message

Ahoora Jafari

Hello,

maybe I good understand, did you try (hope you have relevant backup) unplug Memory card and download prj to PLC? Sry but I don't see reason in this case (you told that there isn't need to backup anything) memory card using. Can you confirm that you can use this solution, or you just have question about functionality?

Duris_I

No I never tried to download without Memory Card!

You mean if there is Memory Card system always upload it from Memory Card? If the answer is yes then you gave me the answer but I have to try and will let you know.

Thanks

You were right, Thanks