Specifications
4 MDS 4790/9790 Series I/O Guide MDS 05-3438A01, Rev. E
Figure 3. Typical Repeater and Polling-Remote Network
Simplex and Switched Carrier Operation
System-wide simplex operation is achieved by switching the master sta-
tion carrier on to transmit, then off to receive. The same frequency is
used for both transmit and receive.
Switched carrier, half-duplex mode works in the same way, except
dif-
ferent
frequencies are used for transmit and receive.
2.4 Features
Reliability is a hallmark of the MDS 4790/9790 design. The radio
employs a one-piece transceiver board which minimizes RF losses and
eliminates the need for inter-board cabling. This also allows easy
plug-in replacement should servicing become necessary.
In addition, the optional redundant version of the radio includes redun-
dant transceiver boards and power supply modules that automatically
become active in the event of a failure in either of the transceiver boards
or power supplies. This ensures continued operation in the event of most
transceiver board failures.
The following list highlights many of the radio’s key features. For a full
listing of specifications, see Section 10.1,
Technical Specifications
,
beginning on Page 93.
–
IDIAG
13
.8 V
D
C
PW
R
+
–
HOST SYSTEM
REMOTE RADIO
RTU
RTU
RTU
RTU
–
I
D
IAG
13
.
8
V
D
C
PWR
+
–
–
ID
I
AG
13
.
8 V
D
C
PW
R
+
–
–
IDIAG
13.8 VDC
PWR
+ –
–
IDIAG
13
.
8 V
D
C
PW
R
+
–
RTU
CONTINUOUSLY
KEYED
REMOTE RADIO
REMOTE RADIO
REMOTE RADIO
REMOTE RADIO
POLLING REMOTE
REPEATER
HALF-DUPLEX
SWITCHED CARRIER
TX HIGH
RX LOW
TX LOW
RX HIGH
TX LOW
RX HIGH
TX LOW
RX HIGH
TX LOW
RX HIGH
TX LOW
RX HIGH
TX LOW
RX HIGH