Every Zigbee network must have one Coordinator node. Developers can use XCTU to set up the node using the instructions from the blog post, Manage Digi XBee Networks Wirelessly with XCTU. Set CE to 1 to enable the coordinator and AP 2 for API mode with escapes. (For modules prior to the Digi XBee3, load the Zigbee coordinator API firmware.) To make testing easier, enable unlimited join time by setting NJ to FF. They will also want to configure some nodes as Zigbee routers. All Digi XBee Zigbee modules ship as routers from the factory.