DALI · How-to guides

Create a parameter

Turn a reading from Modbus, SDI-12, an analog or digital input into a named value the station logs, shows and sends.

Goal: a new named value, such as "Air Temperature" in °C, is logged, shown on the Dashboard, and included in downloads and uploads.

Before you start

You need the Admin role.
The data source already set up: a Modbus or SDI-12 query, or an analog or digital channel. The parameter form only offers sources that exist.
Decide how readings are combined over each logging interval: latest, average, minimum, maximum or running total.

Steps

1
Open the form. Go to Parameters and click + Add Parameter.
2
Name it. Enter a Name (up to 20 characters, unique on the station) and pick a Unit. If yours is not in the list, use + Add custom unit….
3
Pick the source. Set Type, then fill in the fields that appear:
- Modbus (TCP, RS232, RS485, RS485-2): Slave ID, Function Code, Address, Data Type, Byte Order.
- SDI-12: Sensor ID, Request Type, Request Number, Data Index.
- Analog Channel, Aux Analog Channel: Channel Number. Digital Channel: Digital Channel.
- Calculated: see Add a calculated parameter.
4
Set how it is logged. Choose Sampling: Instantaneous, Average, Minimum, Maximum or Cumulative. Set Scaling, Offset (stored value = reading x Scaling + Offset) and Precision (0 to 6 decimals).
5
Optional checks. Turn Range Check on and enter Minimum and Maximum to reject impossible readings. Tick Reset to zero after sunset for irradiance sensors that read slightly above zero at night.
6
Save. Click Save Parameter.

Check it worked

The parameter appears in the list with its Addr (its Modbus slave register), and shows a live value on the Dashboard under Live Parameters.

If something goes wrong

What you see	What to do
Parameter name 'X' already exists.	Names are unique, ignoring capital letters. Choose another.
Maximum 150 parameters allowed.	Delete a parameter you no longer need.
Slave ID is required (or Function Code, Address)	The lists are empty until a Modbus query exists for that bus. Add one first.
Range is enabled: Minimum and Maximum are required (numeric).	Fill in both limits, or turn Range Check off.
A dash instead of a value	The source is not delivering. Check the query or channel.

Order matters to other systems

The list order sets the column order in downloads and each parameter's Modbus slave register. To reorder, drag rows or double-click a number, then Save Order, and tell anyone who reads the station over Modbus. See Modbus slave register map.