Operation
RFI-9256 Radio Modem User Manual
Page 37 of 109
5.3.4 SCADA Protocols
The RFI-9256 supports SCADA protocol networks in two ways:
Providing a point-to-multipoint broadcast network, where any SCADA packet that is inserted at the
master will be delivered to all slaves, and a SCADA packet inserted into any slave is delivered to
the master. This was covered in section 0.
Providing a point-to-multipoint routing network, where master to slave communications is no
longer broadcast. In this case the RFI-9256 will decode each SCADA protocol packet to extract the
destination address and match it against a radio address.
Routing services are provided for a number of SCADA protocols, specifically:
Modbus
Honeywell
DNP3
TDE
PROTOCOL ROUTING
The protocol decoder for the packet based SCADA protocols extracts the destination remote terminal unit
(RTU) address from the protocol and maps it to a radio address. This routing scheme is shown in Figure 12.
Controller
RFI-9256
Master
Main
RFI-9256
Slave
Addr=1000
RTU
Main
Address
SCADA Data
Fcn
CRC
Table
SCADA
Address
Slave Address
Figure 12: SCADA protocol routing
The SCADA protocol routing table on the RFI-9256 can have four types of entries.
Default route:
This route is mostly used by slaves and is a required entry for any slave in a protocol
network. This route only requires the address of the destination radio. This route is used when no
