Hi,

Recently I had to replace an older MM440 with optional DP card, with my general idea in g120 I replaced the MM440 with the new one, but the control board and optional DP Card was still the old one. I did so assuming the program will be saved in the control board. But, I had to commission the MM440 again.

So my question is where is the program stored in MM440? 

Are the control board and optional DP board just for interface and no program is saved in them?

Hello gr8vml;

If by "program" you mean the parameter settings on the MM440 drive, they can be set in RAM (by default) or written to EEPROM for permanent storage. If the settings for parameter sotrage were not set to EEPROM (or if the Write RAM to EEPROM command is not executed by the last programmer), then when power to the drive is taken off the parameter settings are lost.

See thie reply from our friend Piscean 2010 in this discussion:

https://support.industry.siemens.com/tf/ww/en/posts/micromaster-440-memory/185511/?page=0&pageSize=10

As far as the MM Profibus Option board, it acts as a bridge between the PLC and the drive, basically. There are specific PKE (parameter value modification) commands that can force new parameter changes to EEPROM, see table 3-5 of the Profibus Option board manual for example.
https://support.industry.siemens.com/cs/ww/en/view/6586565

Hope this helps,

Daniel Chartier

gr8vml

[snip]

Are the control board and optional DP board just for interface and no program is saved in them?

Yes, EEPROM, RAM  are installed on main motherboard. I/O board is for interafcing digital/analog I/O, optional communication board is for filed bus only. As well explained by our expert dchartier.

HTH.