There are three possible run modes, stop (0), start (1), and suspend (2) with five valid transitions between. A stopped device MUST clear all state and configuration memory, returning to power-on reset (POR) state. If the device was running before being stopped, it MUST NOT deregister from the network, instead it should silently and immediately terminate. A started (running) device operates normally. A suspended device MUST maintain its state data (FAN 1.1 TPS section 6.5.6), but MUST clear its TBU configuration as the TBC will reconfigure any suspended devices on their resumption. Identically to a stopped device, a suspended device MUST NOT deregister from the network. When a suspended device resumes (is set to runMode=1), it MUST restore and use its saved state. Only the following transitions are defined and valid. A stopped device can transition into the start mode once configured, but never into suspend mode. A running device may transition into either stop (clearing its state) or suspend (storing its state) modes. A suspended device may transition into either stop (clearing its state) or start modes (restoring its state). A TBU is assumed to be in the stopped state on boot.