MDS 4710B - Point-To-Point System; Continuously Keyed Versus Switched Carrier Operation

2 MDS 4710B/9710B I/O Guide MDS 05-3316A01, Rev. E
Figure 2. An MAS network provides communications between a central
host computer and remote terminal units (RTUs) or other data collection
devices. The operation of the radio system is transparent to the computer
equipment.
Invisible place holder
Figure 2. Typical MAS network
Point-to-Point System
Where permitted, the transceiver may also be used in a point-to-point
arrangement as shown in Figure 3.
A point-to-point system consists of
just two radios. It provides a simplex or half-duplex communications
link for the transfer of data between two locations. Refer to
Continu-
ously Keyed versus Switched Carrier Operation on page 2
for additional
information.
Invisible place holder
Figure 3. Typical point-to-point link
Continuously Keyed versus Switched Carrier Operation
The keying behavior of the master station can be used to describe an
MAS system.
–
ID
I
AG
13
.8 V
D
C
P
W
R
+ –
HOST SYSTEM
REMOTE RADIO
SWC OFF
RTU
RTU
RTU
RTU
–
IDIAG
1
3
.
8
VD
C
P
W
R
+ –
–
IDIAG
13.8 VDC
PWR
+
–
–
IDIAG
13.8
V
DC
P
W
R
+ –
–
ID
I
AG
1
3.8
VDC
PWR
+
–
RTU
MDS MASTER
STATION
SIDE B
POWER
ORDER
WIRE
CONTINUOUSLY
KEYED
REMOTE RADIO
SWC OFF
REMOTE RADIO
SWC OFF
REMOTE RADIO
SWC OFF
REMOTE RADIO
SWC OFF
HOST
COMPUTER
RTU
SWC ON
SWC ON