Modem module firmware cannot be updated - looping ^SYSSTART | Thales IoT Developer Community
January 18, 2019 - 4:22pm, 3307 views
Hello. My company produces a remote data logging product which incorporates a NimbeLink NL-SW-LTE-GELS3 modem module, which apparently uses a Gemalto modem. We have dozens if not hundreds of these devices in the field, and recently customers have been seeing one of two scenarios: 1) the device works, both answering calls and pushing data to a server, for a week or more, and then stops, requiring a manual power cycle, and 2) often the initial problem then devolves into the modem no longer pushing data or answering calls. It appears that this behavior is initiated when the cell tower operator updates the software used by the cell and it begins to refuse connections from the modems. A hardwired connection to a terminal program reveals the modem is constantly restarting with a ^SYSSTART message. If you type fast or cut and paste, you can sneak in a couple of AT commands between resets, and it seems to respond appropriately. We've tried using the gWinSWup software to upload a new firmware to the modem, but it will only start the transfer for a few seconds and then fails (when the modem restarts). Can anyone offer any suggestions as to how to get around this? The devices were designed for use in harsh environments, and a decision was made years ago to glue them shut permanently except for a few water-tight connectors, and a water-tight plug that can be unscrewed to access the SIM card (and, coincidentally, the USB port on the modem). Direct access to the modem hardware requires physically sawing the case open, rendering it useless. I've been working with NimbeLink support on this, and they're suggesting the firmware was corrupted during a failed update, and there's nothing that can be done via the USB port. As it still responds for a few seconds between restarts, I'm hoping there might be a way to prevent it from restarting, or to disable the existing firmware beyond what's required to push a new version. Any help would be most appreciated!