SLC500 Mem. module (M11) how, when & where to use.

Hello

New at here, new to AB products and relative newbie on PLC-field also.

I have one salvaged SLC500/03 (16kb of mem.) on my desk, with some I/O cards. It also have this 1747-M11 memory module attached (32kb). What I have read and maybe even understood today, is that it seems to be flash-type.

Is there any manuals describing the use of these memory modules?

Does this M11 need sophisticated programming device or does RSLogic500 etc. handle it while attached to CPU? (I use this homebrewed RS232-cable for DF-1 communications)

How and for what the memory module can be used (other than fancy xmas-tree decoration)? Only for big lookup tables, alert storage or or..

Is it active module.. I mean is it possible to write and read it in the user program, if not is there a way to knife the core to allow such thing.

Am I askin too much questions.

Anyway, point was I tried to search, without much luck and google wasn't really helpfull neather.

I think that I don't need such, but selling wouldn't be an option without proper memory reset (because it might include confidential data ...don't know)

PS. The PLC is only for my personal fun and to get understanding to AB logics.

You are asking very good questions.

The memory module is used to store a backup copy of the program with its data tables. It cannot be used to store data gathered by the program while running. It does not expand the running RAM size.

The storage of a program is accomplished while online by the programmer.

Various options can be set as conditions for automatic re-loading of the program from the memory module. Examples are:

Every power up
On power up after automatic clearing of an error
On reset after a memory error is detected by the system.

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1747-um011_-en-p.pdf

http://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1747-rm001_-en-p.pdf

Thank you Bernie for a quick responce.

So if I understood your good answer correctly the only use of memory module is a backup the program and ie. load it in specified circumstances.

That would explain why that manual/forced memory reset (battery off and screwdriver to VBB&GND pins for 60 secs.) didn't work out.

The when & where to use was pretty much there, but how is still hovering around so I ask few more questions.

1) Is there known way to hack it to work as a processor memory extension? (Just yes/No, this is not in my scedule today or next week.)

2) I started to write the 2nd, but.. Then I searched inside the SLC500 manual again (with a new magic words) I got new lead "publication 1747-RM001".

I think this would answer most of my questions if/when the time comes for M11.

Mickey said:

http://literature.rockwellautomation.com/idc/groups/literature/documents/um/1747-um011_-en-p.pdf

http://literature.rockwellautomation.com/idc/groups/literature/documents/rm/1747-rm001_-en-p.pdf

Click to expand...

Thx Mickey, for direct links.

1) Is there known way to hack it to work as a processor memory extension? (Just yes/No, this is not in my scedule today or next week.)

Click to expand...

While you are waiting for bernie.

No

Thx again.

Only use of this module to somewhat extend the program/cpu mem. I could came up with is to use it to store some sort of soft-start data values (ie. for PIDs). Which will be overwritten when the process will give feedback. That kind of soft start wouldn't be possible if there isn't this module in use, me thinks.

Above is the whole idea of this unit..?

Maybe xmas tree doesn't have a new decoration yet.

I could came up with is to use it to store some sort of soft-start data values (ie. for PIDs). Which will be overwritten when the process will give feedback. That kind of soft start wouldn't be possible if there isn't this module in use, me thinks.

Click to expand...

You can do the above with your logic. "When this happens load these values into the PID". Think "MOV" instruction(s).

Loading from the memory module will reload the whole program.

The memory module is a copy of everything. This has advantages and disadvantages. If you set the "Load on Memory Error" bit, and a memory error occurs, on the next power up, the controller will load the contents of the memory module into memory. All of memory. Every timer, counter, program rung, the states of the inputs and output addresses, everything is just as it was when you saved it to the memory module.

This is great in the middle of the night when lightning causes a hard fault, otherwise you might need a laptop to download the program. It also allows anyone with basic knowledge and a metal object to clone the SLC if it needs to be replaced.

The problem lies in that your user settings will be over written and this might happen days months or years later. Also, it often goes unnoticed. The machine quit, we power cycled it, and its been running for two hours...making scrap with last years recipe data...

Another problem is that if you perform online editing, the only way to ensure those edits are stored to the memory module is to put the SLC in program mode for a couple of minutes.

I recommend that if you use a memory module, that you trap and alarm when it is used (there is a system bit "memory module loaded on boot") and provide ladder or HMI logic to ack the alarm and reset that system bit.