ReferenceId: addressing devices directly

Two sensors hang in the boiler room. Both are called “Kessel” because they are averaged together. Now, though, you only want to read the one at the inlet. Names do not help here. Every device, however, has its own fixed number: the ReferenceId.

Reading the ReferenceId#

The ReferenceId is a LogicType like any other, and every device can read it:

l id d0 ReferenceId                               # device on d0
lbn id SENSOR HASH("Einlass") ReferenceId Average # device by name

With lbn this only works if exactly one device matches. With two matches Average builds the mean of two numbers, and that is no longer a valid number. Without a match you get NaN.

l and s with an ID in a register#

If a ReferenceId sits in a register, you put that register where a pin would normally go:

l temp id Temperature        # reads the device with this number
s id On 1                    # writes straight to it

The chip then looks up the device on the data network, without a pin and without a name. That helps when you want to address many identical devices one by one or run out of the six pins.

The ID via define#

If you know the number, it may go straight into a define. A define name in the place of a device counts as a ReferenceId:

define BOILERIN 12345 # ReferenceId of the inlet sensor
l temp BOILERIN Temperature

You read the number once, for instance with s db Setting id onto the housing, and then enter it.