TS4000 Radio Modem User’s Manual
AirNet Packet Protocol
42
A polled system is one where a master (or base) station unit polls a number of
remotes in sequence. The master is always the unit that initiates the
communication and one and only one remote unit responds to the master’s
request. This type of system is very common for SCADA (Supervisory Control
and Data Acquisition) and telemetry systems
Polled System with
Store and Forward
Repeaters
Polled systems are relatively easy to configure and test because the order of
communication is predictable and therefore it is possible to eliminate collisions.
The following section will show a number of system topologies and the
appropriate settings for the TS4000. All of these systems operate on a single
frequency (simplex) although clear channel scan can be used.
Note that the repeater TS4000s can also be connected to host devices and used
as remotes.
There is no forced limit to the number of repeaters that can be in a system.
However, in most cases it is best to use the fewest repeaters possible. Each
additional repeater will add complexity and delay to the system.
