wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

Profiles and Interoperability 5-5
Switch S1
Switch #3200
LON
nvoSwitch
Lamp actuator E1
Lamp actuator #3040
Switch S2
Switch #3200
nviLampValue
nvoSwitch
FIGURE 5.4
Nodes and functional profiles.
The standardization organization for LON (LonMark) has specified “functional profiles” for such a
light control [3]. For the application according to Figure 5.3, two functional profiles have to be considered:
• The switch profile (standardized as No. 3200) defines the function, the configuration parameters,
and the network variables (the types of which are called SNVTs, see below) that are required in
a switch (Figure 5.4). If a user presses the left button on the switch, the microcontroller writes an
“ON”-information into the network-variable nvoSwitch; if the right button is pressed, it writes
an “OFF”-information into this variable. The representation of these values in the variable is
standardized with so-called SNVTs. The nvoSwitch-variable is an output variable and can be
connected to other input variables at other nodes. So each time this variable is changed, its value
is transmitted over the LON network to one or more other automation devices.
Figure 5.4 shows the implementation of the switch profile on two automation devices, which
are switch S1 and switch S2. In this network, the value from the nvo-Switch values must be transmitted
over the LON to the lamp actuator.
• The lamp-actuator-profile (standardized as No. 3040) defines the function, the configuration
parameters, and the network variables that are required in a lamp actuator (Figure 5.4). A network
variable nviLampValue, which is an input variable, is required. If an “ON”-information is
received in this input value from a switch, the lamp actuator switches the lamp on; accordingly,
the lamp is switched off, if an “OFF”-information is received. Figure 5.4 shows the implementation
of one lamp-actuator-profile on one automation device, which is the lamp actuator E1.
In LON, the integration of the automation devices is done with integration tools. With such tools, the
structure of the network and the so-called bindings must be configured. A binding defines the connection
of input variables to output variables.
5.2.3 Logical Nodes of the IEC 61850
The IEC 61850 standard was developed for the communication of devices in substations of electrical
power grids and for distributed energy resources [4–6].
For generic functions like supervision and control of transformers, switches, circuit breakers, and
metering devices, so-called logical node classes were standardized.
For example, the logical node class for a metering device (abbrivated as MMTR according to IEC
61850) includes the following data:
• Health status of the metering device (EEHealth)
• Net apparent energy (TotVAh)
© 2011 by Taylor and Francis Group, LLC