Pandiani

Hello to all,

what are the most important features to be considered when deciding whether to use FM458. I have never use this module before, but I know that this module is for high speed applications. It is used for open and closed loop control when complex arithmetic is used.
What is the speed of this module?
Is it adjustable?
What kind of CPU is needed?

Thanks

Hi

Maybe in manual you'll find some answers. https://support.automation.siemens.com/WW/llisapi.dll/csfetch/14952400/d7sys_funktion_e.pdf?func=cslib.csFetch&nodeid=14951299&forcedownload=true

regards

Hello,

the FM 458 is a function module, you have to program in CFC.

you can use the FM458 in addition to a normal S7 400 CPU.

The main differences are:

-Programming only in CFC with a library called D7-SYS.

-the library has been designed for regulation and arthmetics

-the advantage in CFC is what you see is what you have

-in my opinion easy to read.

-5 realtime tasks adjustable

-the system is coming from drive regulations

-very powerfull system

-full access during commissioning on line changes, with all advantages and disadvantages

-two cards for expansion availabel, (I/O with digital, analog and encoder) and (communication, similink and profibus)

If you need more information, let me know

Hi

It is a wonderful piece of equipment.
I could find just two negatives about it :

a) You have to only use standard libraries available from SIemens. This makes
it a little less flexible for hardcore programmers. ( Although I hear an application
generator is going to be available )

b) Everytime you make any changes in logic and download to FM458, It goes to
STOP and then back to run, unlike S7 CPUs

Nevertheless its sheer performance outweighs these negatives.

Regards
Navnag

You are running 2 FM458 redundant, or

do you want to do this?

Never heard about this.