[?]: MMC Size for my program

[krsh]

Dear colleagues,
I recently purchased a new 315-2DP CPU which i will use for controling a Micromaster 440 VFD, from a Mobile Panel 170, the problem is that i don't know what size to order the MMC for the CPU.
The program is relatively simple it has only 27 inputs and 8 outputs and with approx 10 FC' s and 3-5 DB's.

Thank you in advance.

[CoMod]

How can you determine the size of the load memory and main memory of a SIMATIC S7-300/400 CPU?
http://support.automation.siemens.com/W ... n/36981866
64 KB (36 Euro) is minimum
128 KB (72 Euro) is optimal size for 315-2DP

[peterc101]

looking at youre i/o´s 64kb will be more than enough
personally i think its a waste using a 315-2DP CPU for what you are planning , even the smallest cpu could handle this

[krsh]

peterc101, the idea is to use a CPU with higher performance than necessary because we plan to use it to control other equipment that will be purchased later. Now i know that the MMC i should buy, for the program i mentioned above, is 64Kb. But i will go for the 128 Kb thinking at the upgrade i wil make later.

[Scarch]

For the performance, you have to check the execution time for any instruction, that will determine the scan time of the program, rather than the amount of memory