Port Sharing With Multiple Hosts - GE MDS SD Series Technical Manual

Figure 8. IP/Ethernet Polling Example
The type of network shown in Figure 8 can also be used for general Ethernet bridging as sup-
ported by the over-the-air bandwidth of the system. Bridge filters in the radio may be set to re-
duce Ethernet traffic over the RF channel, and improve performance.

Port Sharing with Multiple Hosts

The transceiver allows for several external data networks to use the same RF network without
confusing the data streams. In such a system, multiple host computers at the Master Unit poll
their respective RTUs, which may be alone or co-located at the Remote sites. Figure 9 shows an
example of such a system. In this case, two host computers (Host A and Host B) are connected to
the Master Unit via the applicable data ports.
At the Remote sites, serial and Ethernet-based RTUs are employed, and responding to a specific
host computer. In the case of the Remote shown on the lower right side of the figure, two RTUs
are co-located, but responding to different host computers and handling entirely different data
streams.
The radio eliminates the need for an external adapter or special external configuration and hand-
shaking when multiple host systems are connected to the network. The radio automatically con-
trols access to the RF channel by multiple hosts when Packet w/MAC is activated. Virtual Radio
Channels (VRCs) are used to separate serial data streams on COM2, COM1, or IP payload ports.
Packet w/MAC operation provides Media Access Control. It is the recommended method of op-
12 SD Series Technical Manual MDS 05-4846A01, Rev. I