The Add Sensor dialog is accessed by clicking on the Add sensor link in the Info panel of the Edit Script dialog when editing an EMS program. With the Add Sensor dialog open you can select from a list of sensors based on the actual model.
At the point the dialog is opened DesignBuilder asks you if you would like to update the list of available sensors by automatically running a preliminary simulation to generate an edd file with a list of all available sensors for the current model. If you agree to this there will be a delay (of several minutes for larger models) while EnergyPlus is run to generate the .edd and .rdd files.
Select the one of the sensors listed in the right hand data panel by either a) double-clicking on the required sensor, or b) by single-clicking on the required sensor and then clicking on the Select 
icon.
When you press the OK button Erl code for the sensor is inserted into the script at the cursor position.
You can get DesignBuilder to set up a DB Erl loop to include script to generate multiple sensors by checking the Add loop checkbox. This allows you to make to make further 2 selections to define the type of loop.
There are 3 different DB Erl Loop types. Select from:
Note: The Model object type defines the type of loop and the type of sensor selected must be compatible. In particular for zone loops, only zone sensors should selected. For surface loops only surface or zone sensors should be selected and for window loops only window or zone sensors should be selected. DesignBuilder checks for incompatible combinations of Model object type and sensor selected and generates an error where appropriate.
The list of loop keywords presented will depend on the Model object type selected as shown below.
When the Model object type selected is 1-Zones, then the list of available loop filter keywords is:
ForAllZones, no filter is applied, i.e. all zones in the building will be listed.
Zone occupancy is defined by the zones' Occupancy density, Floor area per person or Number of people setting (depending on which Occupancy method is selected). If there are people in the space and also if the Zone type is 1-Standard then the zone is considered to be occupied.
Cooling is defined by the zones' Cooled setting on the HVAC model data tab.
Heating is defined by the zones' Heated setting on the HVAC model data tab.
When the Model object type selected is 2-Surfaces, then the list of available loop filter keywords is:
When the Model object type selected is 3-Windows, then the list of available loop filter keywords is:
Enter the name of the sensor to be used in Erl script to reference the current sensor value.
When a sensor is selected from the list, the sensor Name is automatically set to be the name of the sensor but with all illegal characters such as spaces replaced with "_".
Enter a specific object name such as a zone or surface IDF name, or enter "*" to indicate all relevant objects.
When the Add loop option is selected and an appropriate sensor is selected from the list, the sensor Object IDF name is automatically set to be one of:
When a sensor is selected from the list, the sensor Data type field is automatically set. This is the same as the name of the sensor listed and also the name of the EnergyPlus output report used to feed the sensor with its data.
Sensors are based on EnergyPlus outputs so if you would like the output selected for the sensor to also be included in the .eso output file then check this checkbox.
Note: Extra outputs added in this way must be viewed in the Results Viewer and are not generally available for view in the main DesignBuilder results screen.
Select the reporting interval for the selects outputs from the list: