User Manual

6
The communication concept
Communication in the Synco system is based on the KNX standard. This means that
the devices communicate in KNX LTE mode (LTE = Logical Tag Extended) with which
bus communication can be established – with no need for using a software tool. This
mode represents a simple method to build up communication.
LTE mode makes use of zone addresses. Process values are exchanged between all
devices located in the same zone. In contrast to S-mode, a point-to-point assignment
between 2 devices is not required. The exchange of data is effected automatically.
In the case of KNX networks across several lines, the engineering notes given in Ba-
sic Documentation CE1P3127en must be observed (e.g. network structure, number of
devices, type of bus power supply). For central bus power supply, we recommend to
use Siemens’ power supply N 125 from the GAMMA instabus range. It delivers the
system voltage required for the KNX bus.
Before commissioning communication, the following requirements must be satisfied:
• The bus and field devices are installed
• Wiring according to the plant diagram has been checked
• All devices are connected to power
• The bus devices have been configured
• The wiring of all bus device has been checked
• Bus power supply is available
Communication is active when:
• Bus power supply is available
In the case of small plants, it is possible to make use of the internal (decentral) bus
power supply of the Synco 700 controllers (default setting)
Path: … > Commissioning > Communication > Basic settings > Decentral bus
power supply = On
Note: A RDG/RDF/RDU room thermostat consumes 80 % of the bus current pro-
vided by one Synco 700 controller. In case of too many room thermostats, a central
bus power supply has to be integrated, and the decentral power supply of each
Synco 700 controller within the same KNX line has to be turned off
• The device address is entered (every bus user requires an individual device address)
• The bus device is not in commissioning mode
Physical device addressing on the KNX bus
Every bus user (device) must be assigned an individual physical address (network
address). It consists of area, line and device address. Device addressing enables a
device to be identified in a certain area and on a certain line. The Synco bus devices
have area address = 0 and line address = 2 preset.
Setting the device addresses for the Synco 700 RM… devices
Setting the device addresses (1…253) with the help of the operator unit (password
level) or the ACS790 software:
• Path: … > Commissioning > Communication > Basic settings > Enter device
address
Setting the device addresses for the RDG room thermostats and the RXB / RXL
room controllers
Setting the device addresses (1…253) with the help of the ACS790 software or the
buttons (only with RDG, RDF and RDU):
Commissioning –
preparation
Commissioning
Device addressing