If you get a problem with one of the modules, pressing the reset switch until the acknowledge light comes on will reboot the module with the current settings.
Reset and restore to Default settings
If you want to restore to factory default settings then press the reset switch and the acknowledge LED will come on. Release and then press again, this time holding the reset button in until the green Activity LED comes on (about 5 seconds) then release. The green led will remain on for a further 8 seconds then the module will start to run with factory defaults.