Commissioning Instructions

162 / 188
Siemens Web server OZW772.. V9.0 CE1C5701en
Building Technologies KNX S-Mode 2018-10-15
For energy meters, the same data type must be used as specified by the producer
for display purposes. This is the only way to avoid a loss in accuracy on large
numbers, since large floating point numbers it is rounded off to the next displayable
value.
Data points for types 12.xxx, 13.xxx and 14.xxx are labeled with the definition of
the counter medium as energy meter. So that the following data is written once a
day to the consumption data file. See sections:
• Meter medium.
• Identification number.
Data point value
"Meter medium" defines what is actually measured:
A unique identification number of the meter used (0 - 99999999) is entered under
"Identification number".
Data points can have various communication properties. They are defined in KNX
as flags. The flags can be unset (0) or set (1).
Flag
Meaning
Description (for set flag = 1)
C
Communications
Communication is possible via the bus.
R
Read
The data point can be read via the bus.
W
Write
The data point can be described via the bus.
T
Transfer
A change in data point is sent via the bus.
U
Refresh
The data point can be updated by other participants.
Flags are preset on participating devices/actuators/sensors.
Some examples of typical communication properties:
Device function
Set flags
Displays (state, e.g. room temperature)
C W T U
Send (trigger, e.g. light switch)
C T
Send + display (state + trigger, e.g. heating setpoint).
C R W T U
Communication
properties of data
points