S&C Instruction Sheet 1074-510 9
Operation
When the individual data networks are established,
the IP addressing scheme should be planned. In
Figure 1 on page 7. each SpeedNet ME radio host ID
is “1” and each automatic switch control host ID is “2.”
Following a numbering scheme such as this will make it
easier to keep track of which IP addresses are used for
each device.
The SCADA network in this example uses the
192.168.203.0 subnet. This subnet is different than the
subnets used for the Ethernet segments. The wireless
interface of the SpeedNet ME radio from Subnet 1 is
assigned an address of 192.168.203.1. The wireless inter-
face of the SpeedNet ME radio from Subnet 2 is assigned
an address of 192.168.203.2. The wireless interface of the
SpeedNet ME radio from Subnet 3 is assigned an address
of 192.168.203.3.
It would be helpful to draw a diagram as a planning aid
and reference guide when designing the SCADA network.
Routing Options
The SpeedNet ME Mesh End-Point Radio is an end-node
radio and does not participate in building the mesh
network. It does however, connect to a SpeedNet Radio
mesh network capable of providing secure, long-range
communication with high message rates. SpeedNet ME
radios provide a point-to-point wireless connection
between two or more separate Ethernet subnets. Data
are then routed between the Ethernet subnets. Route
information can be entered manually, or it can be pro-
cessed automatically by Ad hoc On-demand Distance
Vector (AODV). See Figure 2 on page 8 for an example of
a wireless network using SpeedNet ME radios with AODV.
AODV routing is a routing protocol for mobile ad hoc
networks and other wireless ad hoc networks. SpeedNet
ME radios use a proprietary AODV routing system that
works dynamically to maintain message routing. It gener-
ates fewer transmissions and conserves network capacity.
In the case of SpeedNet ME radios, AODV will be limited
to discovering and establishing the best possible point-to-
point link. SpeedNet ME radios will not serve as message
relays for other nodes in the network.
Using Static Routes
The routing mode to use (static routes vs. AODV) will be
determined by the present configuration of the network
with respect to roting mode (whether it is using static
routes or AODV). The radios do not support a mixture of
static routes and AODV routing. See Figure 3.
Figure 3. Wireless network using SpeedNet ME radios with static routes.
SpeedNet 1
Ethernet Interface: 192.168.1.1
Wireless Interface: 192.168.3.1
IP Address: 192.168.1.2
SpeedNet 2
Ethernet Interface: 192.168.2.1
Wireless Interface: 192.168.3.2
IP Address: 192.168.2.2
