What brand is your fire fighting host? Generally, CRT is connected to the host through a network card, which has optical fiber and twisted pair. If the CRT is connected to the FAS host through twisted pair, the host can't connect after restarting the line, and the node number of the host must be reset to 0 or 1 after restarting. You can re-determine the node number of the host in the CRT program and change the node number in the FAS host to correspond to the CRT.