Honeywell EN2H-0221GE51 R0808 User Manual

Page of 258
Hydraulic Components 
SDC / DHC  
222 EN2H-0221GE51 
R0808 
Note that bus addresses can only be issued once. Duplicated 
addresses cause problems on the data bus. 
 
7.3.11.2  Control functions via the data bus 
7.3.11.2.1  Boiler start-up protection 
If the selected heat generator operates with boiler start-up 
protection, it signals the status of start-up protection to all the 
corresponding heating circuits. They block the energy tapping 
(pumps off, mixed heating circuit closed) for the period of the 
start-up protection. 
 
7.3.11.2.2  Indirect return increase  
The heat generator in the base unit (addr. 10) transmits its current 
boiler data, and each mixed heating circuit in the system can 
carry out indirect boiler return increase. 
 
7.3.11.2.3  Tank control mode (tank priority operation) 
Each central device can carry out hot-water circuit loading. For 
loading in priority operation, hot-water circuit loading that has 
been started disables all other heating circuits and hot-water 
circuit loading within the bus system. If tank loading occurs in 
parallel operation, all heating circuits in the system remain active 
and an additional hot-water circuit loading with set parallel 
operation can be activated. 
 
7.3.11.2.4  Heating circuit demand 
Each heating circuit demand within the data bus system is 
processed by the base unit (addr. 10). It takes on the greatest 
demand and passes it on to the heat generators as a setpoint 
value. A selected manual mode with manual temperature 
specification also counts as demand. 
 
7.3.11.2.5 Clock 
synchronisation 
The time of day is sent to the entire system by the base unit 
(addr. 10). There is a system time.