The HMM100 has an RS-232 interface on the component board for service use. You can connect to it through the 4-pin M8 service port connector on the module. Vaisala offers an optional USB cable (Vaisala order code 226068) for connecting the module to your PC.
| The service port is intended for short-term use such as calibration. For permanent installation, use the analog output. |
The cable does not provide operation power to the module; you must power it normally through the screw terminals.
If you have not used the HMM100 USB cable before, install first the driver that came with the cable.