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Siemens Heating and D.h.w. Controller RVL481 CE1P2541en
Building Technologies 4 Acquisition of measured values 20.05.2008
4 Acquisition of measured values
4.1 Room temperature (A6, B5)
4.1.1 Measurement
The following choices exist:
• A room temperature sensor QAA24 can be connected to terminal B5
• A room unit QAW50 or QAW70 can be connected to terminal A6
• 2 units can be connected to the terminals. In this case, the RVL481 can ascertain the
average of the 2 measurements. The other room unit functions will not be affected by
averaging
4.1.2 Handling faults
If there is a short-circuit or open-circuit in one of the 2 measuring circuits, the control
responds as follows, depending on the room temperature source (setting on operating
line 65):
• No sensor (operating line 65 = 0):
A short-circuit or open-circuit has no impact on the control. An error message will not
be generated
• Room unit sensor QAW… (operating line 65 = 1):
In the event of a short-circuit or open-circuit, the control continues to operate with the
room model, depending on the function. An error message will be generated
• Room temperature sensor QAA24 (operating line 65 = 2):
In the event of a short-circuit or open-circuit, the control continues to operate with the
room model, depending on the function. An error message will be generated
• Average value (operating line 65 = 3):
In the event of a short-circuit or open-circuit in one of the 2 measuring circuits, the con-
trol continues to operate with the normally working measuring circuit. An error mes-
sage will be generated.
In the case of a short-circuit or open-circuit in both measuring circuits, the control con-
tinues to operate with the room model, depending on the function. 2 error messages
will be generated
• Automatic mode (operating line 65 = A):
Since the controller itself decides how it acquires the room temperature, error mes-
sages cannot be generated.
4.1.3 Room model
The RVL481 features a room model. It simulates the progression of the room tempera-
ture. In plants with no measurement of the room temperature, it can provide certain
room functions (e.g. quick setback).
For more detailed information, refer to section 0 "
Room model temperature".
4.2 Flow and boiler temperature (B1)
4.2.1 Measurement
The flow or boiler temperature is acquired with one LG-Ni 1000 sensor.
Averaging with 2 sensors is not possible.
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