Siemens Building Technologies
Basic Documentation RVL470
CE1P2522E / 30.03.2000
Landis & Staefa Division
Function block "Service functions and general settings"
49/68
heating circuit. If the boiler temperature controller is in segment 1…14, it will deliver the
critical locking signal only to all loads in the same segment and – if present – to its own
heating circuit.
Minimum limitation of the return temperature can also be provided locally by a controller
with plant type no. 1. In that case, the critical locking signal only acts inside the control-
ler and is only delivered to the own heating circuit.
With regard to the response of the loads and heat exchangers, there are two choices:
•
Heat exchangers and loads with mixing valve:
The flow temperature setpoint will be reduced in function of the set locking signal gain.
Heat exchangers and loads close their mixing valves
•
Loads with pump circuit:
When a defined value of the critical locking signal is reached, the pump will be deacti-
vated, independent of the set locking signal gain.
13.5. Entries for LPB
13.5.1. Source of time of day
Depending on the master clock, different sources can be used for the time of day. It
must be entered on the RVL470 (0…3 on operating line 178):
0 = autonomous clock in the RVL470
1 = time of day from the bus; clock (slave) with no remote readjustment
2 = time of day from the bus; clock (slave) with remote readjustment
3 = time of day from the bus; central clock (master)
The effect of the individual entries is as follows:
Entry Effect
Diagram
0
•
The time of day on the controller can be read-
justed
•
The controller's time of day is not matched to
the system time
Controller time
System time
Adjustment
1
•
The time of day on the controller cannot be
readjusted
•
The controller's time of day is automatically
and continually matched to the system time
System time
Adjustment
Controller time
2
•
The time of day on the controller can be read-
justed and, at the same time, readjusts the
system time since the change is adopted by
the master
•
The controller's time of day is nevertheless
automatically and continually matched to the
system time
System time
Adjustment
Controller time
3
•
The time of day on the controller can be read-
justed and, at the same time, readjusts the sys-
tem time
•
The controller time is used as a presetting for the
system
25
22B
12
e
System time
Adjustment
Controller time
In each system, only one controller may be used as a master. If several controllers are
set as masters, a fault status signal will be delivered (error code 100).
