3-1
SECTION 3. RADIOTELEMETRY NETWORK COMPONENTS
3.1 THE RF95T MODEM
As with the CR10 and CR10T datalogger, there
are enough changes to the RF modems to
warrant a new model name
hence the RF95T
and the RF232T. The RF95T and the RF232T
differ from the RF95 and RF232 in the following
respects:
•
The “T” versions use a new protocol
requiring a different PROM.
•
The “T” versions are not supported by PC208.
•
The “T” versions use a larger capacity
RAM chip.
RF95 and RF232 modems can be updated by
purchasing an upgrade kit with the new PROM
and RAM chip for serial numbers starting at about
1491. RF95 modems that are older than this had
the RAM chip soldered in place and should be
returned to Campbell Scientific for the necessary
modifications. The DC95 modem and SDC
hardware can't be used or upgraded.
The following capabilities are important when
using RTMS, CR10T, and RF95T modems:
•
A maximum depth of four repeaters can be
used.
•
150 is maximum number of remote RF95T-
CR10T site that may be used with an
RFBase. A maximum of 254 remotes can
be used on a PC.
•
Phone to RFBase stations with a CR10T at
the site are NOT supported
•
RF95T and RF232T modems can't be used
in a network containing RF95 and RF232
modems.
•
CR10, 21X, and CR7 dataloggers can't be
used with RF95T and RF232T modems.
3.1.1 PHYSICAL DESCRIPTION
The front panel of the RF95T is shown in Figure
3-1. There are two ports for interfacing external
devices. The port labeled TRANSCEIVER
connects to the radio, and the port labeled SERIAL
I/O connects to the datalogger, PS512M or
CH512R in the case of a repeater or phone-to-RF
base station. The red light labeled CARRIER
DETECT is used primarily to indicate when a
carrier frequency has been detected by the radio.
This is explained later in further detail.
FIGURE 3-1. The RF95T Modem
