SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS
3-2
3.1.2 RF95T STATES
The ninth switch should be set in the RF95T-ME
state (switch nine should be open, represented by
a 1). Refer to Figure 3-2. The RF95T is shipped
with the switch set for the RF95T-ME state.
TABLE 3-1. A Sample of Station ID Numbers
and the Corresponding Switch Settings
Station
Switch Settings
ID
1234
56789
0
0000
0000X
10
0101
0000X
20
0010
1000X
30
0111
1000X
40
0001
0100X
50
0100
1100X
60
0011
1100X
70
0110
0010X
80
0000
1010X
90
0101
1010X
100
0010
0110X
110
0111
0110X
120
0001
1110X
130
0100
0001X
*
Station ID 255 is reserved for
phone-to-RF base stations.
3.1.3 SETTING STATION ID
Each RF95T must have a Station ID, which is
similar to a phone number. This allows one
base station to communicate with any one
particular field station.
The Station ID can be any number from 1 to
255, the Station ID is set with the switch inside
the RF95T. The first eight dip switches are
used to set the Station ID. Table 3-1 shows the
switch setting for several Station IDs numbers,
Appendix A shows all possible Station ID
numbers. The dip switches can either be open,
represented by 1, or closed, represented by 0;
X in Table 3-1 refers to "don't care." The ninth
dip switch is set according to the desired RF95T
state, see Section 3.1.2 "RF95T States." The
RF95T is shipped with a Station ID of 1, and is
set in the RF95T-ME state.
FIGURE 3-2. Setting the Station ID
3.1.4 THE CARRIER DETECT LIGHT
The Carrier Detect Light on the front panel of
the RF95T has several purposes. The primary
function of the light is to indicate when data is
being received or transmitted. The light will stay
on when a network frequency originating from
another RF95T is detected. If a signal is
detected that isn't intended for that station, the
light will shut off after about two-tenths of a
second.
The Carrier Detect Light can also be used to
check the RAM (Random Access Memory) and
ROM (Read Only Memory) of the RF95T. With
the radio disconnected and the datalogger in
the LOG (*0) Mode, connect the datalogger to
the RF95T Serial I/O Port with a 9-pin ribbon
cable. The sequence of the light flashing after
connection indicates the RAM and ROM status.
Both the RAM and ROM are good if the light
goes on for one second, off for one second, and
then back on for one second. The RAM is
faulty if the light is on for one half second and
off for one half second, continuously. The ROM
is faulty if the light goes on for one second, off
for one half second, on for one half second, and
then off for one half second, continuously.
3.1.5 THEORY OF OPERATION
Understanding how the radio network works will
aid in both designing and maintaining a RF
network. The communication between the
computer and the dataloggers in a radio
network are managed by the RFBase and occur
somewhat independently of the computer.
There are two basic packet delivery techniques
provided by the RF232T (RFBase) and the
RF95T (remote) modems; direct maintenance
and polling. These are described in the
following sections.
