4.6 UDP level distribution

Polling the power sensor by means of HTTP GET requests via the network interfaces is limited in speed. The power sensor may be polled about three times a second this way.

To overcome this limitation, the power sensor provides the capability to distribute the measured level as UDP datagrams. It does this in real time as the values are sampled by the power sensor (20 samples per second).

Protocol Definition

The UDP datagrams are sent to a configurable IP address at port 2000. Each datagram carries the actual measurement value as a zero-terminated string. Hence, if the power sensor is configured to make plain level measurements, the UDP datagrams contain something like '-25.33' which represents the measured level in dBm.

UDP datagrams are sent each time the power sensor measures the input level.

Configuration

To use the UDP feature, enter a valid IP address to the "UDP destination address" field at the Setup page or set this parameter from remore with the ' udpa ' remote parameter.

The power sensor starts to send UDP datagrams as soon as it receives a valid destination IP address. To stop the UDP distribution, set the destination address value to 'none'.

Beside definite IP addresses, the power sensor also accepts UDP broadcast masks for the "UDP destination address" parameter. In this case, the power sensor sends the datagrams as UPD broadcasts, multiple clients may receive the measurement value in this mode. When using UDP broadcasts you should consider the following:

• Other computers in the same network which listen to UDP datagrams at port 2000 may be disturbed by the data send by the power sensor.
• You must not enable UDP broadcasts for more than one power sensor in a network. Receivers of the UPD messages might fail to distinguish the messages coming from different power sensors.
• IP routers, also some sorts of switches deny to forward UPD broadcasts unless they are explicitly configured to do so.