MDS 05-3305A01, Rev. E
MDS 4710/9710 Technical Manual
13
Enable Sleep Mode through RTU control by asserting a ground on Pin
12 of the radio's
DATA INTERFACE
connector. When Pin 12 is opened,
the radio will be ready to receive data after a delay period that varies
with modem type. With
MODEM NONE
, the delay will be less than 75 ms.
Digital modems will typically require an additional 60 to 100 ms to res-
ceive data when receiving a continuous keyed master station. This addi-
tional delay is reduced to less than 20 ms when receiving a switch-keyed
master station.
NOTE:
GE MDS recommends against applying RS-232 voltages to
Pin 12 of the radio’s DB 25 connector. Only apply ground or
+5 Vdc to this pin. GE MDS recommends that you connect the
radio and RTU using the circuit shown in
Figure 7
.
For information on using an ABB Totalflow meter to control
the radio’s sleep mode, refer to
GE MDS Product Bulletin
PB-0904
.
Figure 7. RTU to Pin 12 Interconnect Circuit
System Example
The following example describes Sleep Mode implementation in a typ-
ical system. Use this information to configure a system that meets your
particular needs.
Sleep Mode Example:
You need communication to each remote site only once per hour.
Program the RTU to raise an RS-232 line once each hour (DTR,
for example), and wait for a poll and response before lowering it
again. Connect this line to Pin 12 of the radio’s
DATA INTERFACE
connector. This allows each RTU to be polled once per hour with
a significant savings in power consumption.
Invisible place holder
3.0
OPERATION
In-service operation of the transceiver is completely automatic. Once
the unit is properly installed and configured, operator actions are limited
to observing the front panel LED status indicators for proper operation.
DIODE
DIODE
3.3 k
RESISTOR
RS-232 INPUT
PIN 12
RADIO’S DB-25
CONNECTOR
PIN 12
NOTE: USE SWITCHING TYPE DIODES
(FOR EXAMPLE, 1N914)