is it easy to convert from mc42fs to ms43fs

if it’s just digital I/O expansion you need, easiest is to add a xc21 or similar on an expansion bus of the master if you have one available

If it’s analogue then an xc4 expansion unit is your best option- either way your existing master and wiring can remain as is

another great idea ! thank you. slick module

I would consider it to be quite easy. 

-Add the MC43FS to the system.

-In the MC42 application, Ctr-A to mark everything, drag and drop to MC43FS application

-On the MC42 block diagram, Ctrl-A to mark everything, drag and drop to MC43FS application

-In system layout, click on the CAN bus connections on the MC42 and drag over to MC43FS.

-Under the list of logs for the MC42, select the logs you have defined yourself (not system log) and drag and drop to MC43FS logs. 

Delete the MC42 and you are good to go. 

If you happen to have settings files taken from the previous module, these cannot be used with the new master. 

If you have already deployed MC42 modules in the field, then it is more problematic. You would end up with two separate but similar project files to maintain. In that case the suggestion that Andy made about adding an expansion may be better. 

Thank you for that ! nice