Is Ethernet really the magic cure-all communication protocol?
Coulter: For SCADA Communication Ethernet does not function well in the last mile radio links. Although there are Ethernet radios, often many energy companies are using licensed spectrum radios with 12.5 khz bandwidth, liming data rates to 9.6 or 19.2 Kbt. The protocols, like Modbus, are very efficient, but the addition of Ethernet overhead will significantly impact the efficiency of the channel, limiting the number of remotes or messages that can be carried either direction. The concept of Ethernet and standard Ethernet encryption tools as a solution to SCADA security has many issues to overcome as well as a massive number of embedded systems. We actually use Ethernet at the Polling engines which talk out over the network Ethernet. Strategically located terminal servers then translate into serial communication in the last mile links (radio or satellite systems). I believe most energy companies are generally doing something similar. Charles: Ethernet and serial communications will like
