VLT
®
6000 HVAC
33
MG.60.B1.02 - VLT is a registered Danfoss trademark
Introduction to
HV
AC
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Fieldbus protocols
Danfoss VLT frequency converters are able to fulfil
many different functions in an automated building
management system. The VLT frequency converter
can be integrated directly in an overall monitoring
system.
This means that detailed process data can be
transmitted via serial communication. The protocols
listed below are based on a RS 485 bus system with
a maximum transmission speed of 9600 bauds.
As standard, the following protocols are supported:
- Danfoss FC protocol
- Johnson's Control Metasys N2
- Landis/Staefa FLN
1)
1)
Available from approx. October 1998.
A frequency converter can be set and applied in all
building management control systems.
Status messages, warnings and alarms provide
valuable assistance in visualising and assessing
processes.
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Fieldbus options
The increasing need for information in building
management systems makes it necessary to collect
or visualise many different types of process data.
Important process data can help the system
technician in the day-by-day monitoring of the
system, which means that a negative development -
e.g. an increase in energy consumption - can be
rectified in time.
The substantial amount of data in large buildings may
generate a need for a higher transmission speed than
9600 bauds. Danfoss VLT 6000 HVAC is available
with LonWorks
®
or Profibus
®
, both of which have
higher performance than standard integrated serial
communication.
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Profibus
Profibus is a fieldbus system with FMS and DP, which
can be used for linking automation units, such as
sensors and actuators, to the controls by means of a
two-conductor cable.
Profibus FMS
FMS
FMS
FMS
FMS is used if major communication tasks
are to be solved at cell and system level by means of
large volumes of data.
Profibus DP
DP
DP
DP
DP is an extremely fast communication
protocol, made specially for communication between
the automation system and various units.
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LON - Local Operating Network
LonWorks is an intelligent fieldbus system which
improves the possibility of decentralising control, as
communication is enabled between individual units in
the same system (Peer-to-Peer).
This means that there is no need for a big main
station for handling all the signals of the system
(Master-Slave). Signals are sent direct to the unit that
needs them via a common network medium. This
makes communication much more flexible and the
central building state control and monitoring system
can be changed into a dedicated building state
monitoring system whose task is to ensure that
everything is running as planned. If the potential of
LonWorks is fully utilised, sensors will also be
connected to the bus, which means that a sensor
signal can quickly be moved to another controller. If
room dividers are mobile, this is a particularly useful
feature.
Two feedback signals can be linked to the VLT 6000
HVAC by means of LonWorks, thereby enabling the
internal PID regulator to regulate directly on the bus
feedback.
