User's Manual

ESTABLISHING COMMUNICATION LINKS
©
©©
© RF Innovations Pty Ltd, 1998 Page: 76
234839, Revision 2.2
9 Establishing Communication Links
10
Point to Point
he RFI-9256’s versatility allows data communication links to be established using a variety of different
configurations. This, in turn, makes it possible to extend the range of RFI-9256’s and get around
obstacles.
Figure 9-1 and Figure 9-2 show the most common and straightforward link, a master communicating to a
slave in a dedicated link. Both radios should be set to point to point (direct).
Once selected, and
the menus have been
exited, this mode
automatically connects
the modems and
establishes a
communication link.
Communication is
no longer
controlled by the AT commands. In this mode the units are always connected
and the
NETWORK LINK
LED and
ON LINE
should always be ON. The
CARRIER DETECT
LED is used
to indicate the link quality, by the ratio of green to red (if the LED is green 100% of the time, the link is
perfect). The
CARRIER DETECT
LED on the slave will always indicate the link quality. On the Master the
link quality is indicated
more accurately when it
is running a Margin
Link Test.
Point to Multipoint
Dial connection
A point to multipoint dial connection behaves just like a telephone line modem. By using the ATDT
command followed by the number of the slave, the slave will then be connected to the master. This allows
two RFI-9256 radio modems to look like a direct telephone line connection. Only one slave can be
connected to the master at any one time in this mode, but the master can communicate with any slave
within its network. For this mode to be enabled the radio’s in the network must be configured as point to
multipoint (dial) modems.
10
This section is concerned with the
logical
configuration and set up of networks.
T
Figure 9-1 Point-to-Point Local Connection
Fi
g
ure 9-2 Point-to-Point Ph
y
sical Connection