Extended commands

Many sensors support extended SDI-12 commands. An extended command is specific to a make of sensor and tells the sensor to perform a specific task. They have the following structure. Responses vary from unit to unit. See the sensor manual for specifics.

Command: aXNNNN!

The command will start with the sensor address (a), followed by an X then a set of optional letters, and terminate with an exclamation point.

Response: a<optional values><CR><LF>

The response will start with the sensor address and end with a carriage return/line feed.