A temperature sensor on a machine takes one reading a second. When the machine runs hot, the fan has to come on right away, whether or not the plant’s Wi-Fi is working. In the Alpha demo this device runs the AltSql engine on 64 KB of flash with 1,048 bytes of engine RAM, and it makes that call by itself.

The run covers one simulated hour. Wi-Fi drops out from minute 20 to minute 35. Two gateways listen: gateway A receives every record, and gateway B, which stands in for a constrained link, receives only the minute summaries and the fan state.