ZFR1800 Series Wireless Field Bus System Technical Bulletin42
6. Click Scan to connect to the mesh. The ZFR USB dongle LED flashes rapidly
(approximately three times a second) until it successfully joins the mesh. The
LED illuminates solid after successfully joining the mesh.The LED flashes
during communication with wirelessly enabled field controllers.
If the ZFR USB dongle cannot join the mesh after 1 minute, the LED turns off.
See ZFR USB Dongle Troubleshooting to diagnose why the ZFR dongle could
not join the wireless mesh.