It is strange how questions tend to come in cycles. In the last month we have received multiple requests relating to accessing the points on XT9100 devices attached to the expansion bus of a DX9100. So, this automatically becomes a FAQ.
In this case, the DX-9100 acts as a gateway and exposes the XT9100 to the N2 bus. So, you will find the XT module on the N2 bus when you do a discovery using the configure wizard in our S4 Open Management Console. You need to keep this device in the building control network folder and in the network connections folder so that it can be directly accessed for any reason. Other than this recommendation you can ignore the presence of the XT9100 as a discrete device on the N2 bus. You can also ignore the default points list assigned to the XT9100 in the Building Control Network.
The configuration options for the XT9100 inside the DX9100 configuration tool (GX9100) you will see that one of the things that it asks you to do is choose a N2 address for the device. This address must be unique just as if the XT9100 was physically on the N2 bus. This is because of the functionality in the DX9100 that exposes the XT9100 to the N2 bus.
All points on XT9100 devices will be defined and accessible through the DX9100 database as if they were physically a part of the DX-9100. Since each DX-9100 is custom programmed, the database in each DX9100 will accurately reflect the point naming and usage for any attached XT9100 devices. Therefore, the best way to work with XT9100 devices is simply to access its points through the database of its host DX-9100.
This discussion only applies when the XT-9100 is connected to the expansion bus of a DX9100. If an XT9100 device is connected physically to a N2 bus the answer will be different.