Using the M580 DTM browser it slightly frustrating since even the slightest change like adding or renaming a generic modbus TCP variable in a request results in a build offline requirement.
I can understand that when changing modbus addresses or RD/WR lengths triggers a build offline but working within a already defined request should definitely be allowed with online change.
I'm thinking about how this worked in the older Premium/M340 system where defining something in the I/O scanner triggered a offline build but once the data was in the %MW area you could do what you want with it using normal program changes online.
In a large plant you don't want PLC stops all the time for even the smallest communication changes so in this manner I think the M580 way is a huge step backwards and makes it very hard to use a M580 for a larger plant.
So I would like to propose that doing changes inside a already defined modbus request should be allowed using just a online build of the changes.
Maybe it could be done using a slightly extended program/task cycle like some other PLC manufacturers do bigger changes instead of forcing a complete program stop?