An A205 is required to write the radio address of the wireless base station to the wireless sensor firmware so that the sensor will respond to polling from the base station. This is done using the Device Configuration Utility software. The A205 is also useful for connecting a computer directly to the CWS655, CWS220, or CWS900 for diagnosis, changing the base station radio address, uploading new firmware, and verifying sensor functionality. It is only necessary to purchase one A205—unless multiple users with multiple computers need to perform these tasks.