Operating Instructions
Table Of Contents
- RXB (KNX) applications library
- RXB Description of functions for FC10, FC11, FC12, FC13
- Table of contents
- 1 Introduction
- 2 Definitions / Tools
- 3 Select communication mode
- 4 Applications, parameters
- 5 Room operating modes
- 5.1 Description
- 5.2 Overview
- 5.3 Determine the room operating mode in Desigo (S-mode)
- 5.3.1 Local control of room operating mode via a window contact
- 5.3.2 Central control of room operating mode via input from the Use time schedule
- 5.3.3 Central and local control of room operating modebased on occupancy
- 5.3.4 Central control of room operating mode viathe Room operating mode time schedule
- 5.3.5 Local control of room operating mode with a room unit
- 5.3.6 Local control of room operating mode via the Temporary Comfort mode input
- 5.3.7 Effective room operating mode
- 5.3.8 Desigo examples
- 5.4 Determine the room operating mode with third-party products (S-mode)
- 5.4.1 Local control of room operating mode via the window contact input
- 5.4.2 Central control of room operating mode via the Room operating mode time schedule
- 5.4.3 Central control of room operating mode via the Use and Occupancy time schedules
- 5.4.4 Central and local control of room operating modebased on occupancy
- 5.4.5 Local control of room operating mode with a room unit
- 5.4.6 Local control of room operating mode via the Temporary Comfort mode input
- 5.4.7 Effective room operating mode
- 5.4.8 Third-party (S-mode) examples
- 5.5 Determine the room operating mode with Synco (LTE mode)
- 5.5.1 Local control of room operating mode via the window contact input
- 5.5.2 Central control of the room operating mode via Enable Comfort
- 5.5.3 Central control of room operating mode via Room operating mode input
- 5.5.4 Local control of room operating mode via presence detector
- 5.5.5 Local control of room operating mode with a room unit
- 5.5.6 LTE-Mode Examples
- 5.6 Determine the room operating mode without a bus (stand-alone)
- 6 Setpoint calculation
- 7 Temperature measurement
- 8 Control sequences
- 9 Fan control
- 10 Master/slave
- 11 General and central functions
- 11.1 Send heartbeat and receive timeouts
- 11.2 Digital inputs
- 11.3 Temporary Comfort mode
- 11.4 Presence detector switch-on and switchoff delay
- 11.5 Heating and cooling demand
- 11.6 Heating/cooling signal output
- 11.7 Special functions
- 11.8 Boost heating (Morning Warmup, 2)
- 11.9 Night purge (Night Purge, 4), (FNC10, FNC12)
- 11.10 Precooling (Precool, 5)
- 11.11 Test mode (Test, 7)
- 11.12 Emergency heating (Emergency Heat, 8)
- 11.13 Rapid ventilation (Fan only, 9)
- 11.14 Free cooling (Freecool, 10)
- 11.15 Alarm
- 11.16 Reset the setpoint shift
- 11.17 Free inputs/outputs
- 11.18 Software version
- 11.19 Device state
- 12 Room unit
- 13 KNX information
- 14 FAQs
- 15 Integrate RXB in Desigo/Synco
- 15.1 Case 1: Integration into Synco
- 15.2 Case 2: Integration into Desigo
- 15.3 Case 3: Display in Desigo, with shared Synco time scheduler
- 15.4 Case 4: Display in Desigo/Synco, with shared Synco time scheduler
- 15.5 Case 5: Display in Desigo, andseparate time schedulers
- 15.6 Case 6: Separate display, andseparate time schedulers
- 15.7 Case 7: Separate display, andshared Synco time scheduler
- 16 Working with different tools
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Siemens RXB (KNX) application library RXB Description of functions for FC-10, FC-11, FC-12, FC-13 CM110385en_08
Building Technologies KNX information 2013-06-17
13.3 Startup delay
After a reset, it takes up to 5 minutes for all the connected room controllers to restart.
This is designed to avoid overloading the mains power supply when restarting. At the
same time, it reduces the load on the KNX network, as not all controllers transmit data
at the same time.
The delay is determined by the controller's device address.
13.4 Bus load
In a large KNX system, the bus load can be a problem, especially with central
commands which cause the controllers to send status information simultaneously. This
can even result in the loss of data telegrams.
The management station is normally connected to the KNX bus via the area line.
Special attention needs to be paid to the load on the bus to avoid a bottleneck on
the area line. A bus load which may be acceptable on individual lines causes an
overload on the main lines and the area line.
To avoid a KNX communications overload, note the following rules and precautions:
• Define a rational topology, divided into lines and areas.
• If possible, avoid functions across lines: Place sensors and actuators on the same
line.
• Load filter tables for the line and area couplers so that the entire system is not
burdened with information which is only required locally.
• Be rational about integration into a management station or display: Only integrate
information which is genuinely needed.
• For status messages, automatic transmission is not necessary if the display device
can actively read the values. The flags must be set accordingly in the ETS.
• Do not define too short an interval.
• Central commands which affect a large number of controllers should be divided over
several group addresses, and transmission should be staggered.
• Each group address must have a receiver to acknowledge the telegram, otherwise
unwanted repeat-telegrams are generated.
• For additional hints for reducing the bus load see pages 24 and 91.