The sub-point Service > Settings > Monitoring > Channel Assignment allows you to assign monitoring windows to a control channel. A so called control channel is mostly an "NC channel" (Siemens) or a "path" (Fanuc).
You can determine which monitoring channel is to be fed from which control channel.
This is advisable if a machine has two spindles, for example. Each control information channel sends its own Profibus information for all parameters, such as tool number, processing number, etc. This means that in monitoring channel 1, for example, tool 1 is running, while at the same time tool 2 is running in monitoring channel 2.