I would use a tag change script instead of a timer script. That way the script will only run when M1 changes rather than every 250 ms. You can create a tag change script in the Event Scripts (Gateway). You don’t want to create a client event script since it requires a client to be open and it will run on every client.
When you create a tag change script you want to tell it which tag to listen on. In your case the tag is FX3U/M1. The script will look like this:value = newValue.value
system.tag.writeToTag("FX3U/M2", value)So whenever M1 changes it will write it to M2.
Another way you can accomplish this is outside of scripting. You can create a DB tag in the SQLTags browser through the right click menu on the Tags folder. The DB tag will be an expression (select expression mode from Expression/SQL tab). The expression will just point to the M1 tag like this:{FX3U/M1}Below you have the ability to write the value of the DB tag to another tag. You can select M2. This does the same thing as the script but easier to setup and to find.
Hope this helps. Let me know if you get stuck.