Siemens RVD240 - Bus Power Supply; Outside Temperature Source

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Siemens Building Technologies Basic documentation RVD240 CE1P2384en
HVAC Products 20 Function block LPB parameters 27.05.2004
2
• The time of day on the controller can be
readjusted and, at the same time, read-
justs the system time since the change
is adopted by the master
• The controller's time of day is neverthe-
less automatically and continually
matched to the system time
System time
Adjustment
Controller time
3
• The time of day on the controller can be
readjusted and, at the same time, read-
justs the system time
• The controller time is used as a pre-
setting for the system
2522B12e
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).
20.2.3 Bus power supply
In interconnected plants with a maximum of 16 controllers, the bus power supply may
be decentralized, that is, power may be supplied via each connected device. If a plant
contains more than 16 devices, a central bus power supply is mandatory.
On each connected device, it is then necessary to set whether the data bus is powered
centrally or decentrally by each controller.
With the RVD240, this setting is to be made on operating line 134. The current setting
is shown on the left and the current bus power supply status on the right.
Display Automatic bus power supply on the controller Bus power supply
currently present
0 0
No
0 1
Bus power supply is central (no power supply via
controller)
Yes
A 0
No
A 1
On, decentral bus power supply by the controller
Yes
The word BUS appears on the display only when the bus address is valid and when
bus power supply is available. This means the display indicates whether or not data
traffic via the data bus is possible.
20.2.4 Outside temperature source
If, in interconnected plants, the outside temperature is adopted from the data bus, the
temperature source can be addressed either automatically or directly (operating line
135).
Addressing Display, entry Explanation
Automatically A ss.gg xx = segment number
gg = device number
Directly ss.gg To be entered is the address of the outside
temperature source
If the controller is operated autonomously (with no bus), there will be no display and no
entry can be made.
If the controller is used in an interconnected plant and if it has its own outside sensor, it
is not possible to enter an address (if an entry is made, the display shows OFF). In that
case, the controller always uses the outside temperature signal delivered by its own
sensor. The address displayed is its own.
For detailed information about addressing the outside temperature source, refer to Data
Sheet N2030.