It is true that the ASL DS 4000 M Matrix is different to other Matrix systems. The DS 4000M has 5 so called string out connectors and you can connect up to 8 user stations to each string in either daisy-chain, star configuration - using an ASL Hub - or line configuration going through Wall boxes. If you use daisy-chain, it is not like in an analogue systems, where everyone on the same cable would be talking to the same groups, but you can program each user station on that string to be in different groups.
One does have to make groups first and assign these groups to the channels of the user station. However, a group can consist of only 2 stations allowing therefore a “person to person” connection. The extra feature of PTP on the ASL intercom system allows to talk privately (like a telephone call) to anyone connected to the system without having to be pre-programmed. This is done by scrolling through the list of all connected users or by dialing the ID numbers of the requested user. While being on the PTP call, the intercom signals can be dimmed to a preset level, to still be able to listen to what is going on in the programmed group conversations.