The M700/M900 DECT base station can be used as a single cell or as a multi cell system. To configure the M700/M900 as a multicell, a base station with access data is registered on the respective PBX (here an example on the 3CX) and this is switched to Multicell "Enabled". Thus, this base automatically becomes the Primary base and every further base becomes a secondary base of the same network after switching on the Multicell mode, as long as you have used the same "System Chain ID". How the configuration works in detail can be seen in the following description.
The Complete Article, how to setup a Multicell can you find here: DECT - 3.0 Multicell setup
ATTENTION: If you want to create a multi-cell, you must fully set up at least one base as the primary base. This will then display "Allowed to join as primary base". Only when the primary base exists can you add other bases as "secondary bases".
First you enter the IP address of the first M700/M900 base station in your web browser and
use the default credentials for "username" and "password": admin
How to find the IP address of your base is described in the following article: How to enter M300, M700, M900 - Web Interface
Please switch the item "Multi cell system" to "Enabled".
After you have accepted this setting, the view of the start page changes as follows after a short time:
" Multi cell Unchained - Allowed to Join as Primary "
Now you have prepared everything for the multicell and you can add more bases that report as secondary bases.
And after a few moments, when the first secondary base has synchronized with the Primary base, the view changes again:
For other secondary bases, synchronization may vary depending on the size of the multicell.
→ If you want to add more bases to your multicell, proceed in the same way as adding the second base station.