S7-300 ->Support device replacement without exchangeable medium, meaning?

Hi,



Can some explain me what's the measining of this option inside hardware configuration.

When should I want/need this option to be on/selected and when should I want/need this option to be

off.

It is for assigning the Profinet Device Name via the network topology, rather than via a memory card.

Funnily enough i have just spoken to someone from Siemens about this, as when i compiled an existing project i received a warning:

Warning: The "Replace device without exchangeable medium" function cannot be used for IO device.

What does this mean if i downloaded the project?

Normally, when a Profinet device needs to be replaced, the new device needs to get the device name assigned before it will talk to the PLC. Normally this would require you to get your laptop out.

Some devices simplify this by having memory cards that you can move from the old to the new, that carry the device name over (device replacement WITH exchangable medium), no laptop required.

If the device supports it, and this option is checked, then the PLC can automatically assign the device name. The PLC knows that a device of XYZ type USED to be connected to the network at the end of this cable. When a new device of the same time (usually at factory default comm settings) shows up at the same place on the network, the PLC recognizes that it is the "same" device, assigns the name, and then they are up and talking.