MDS 05-3447A01, Rev. F
MDS 1710A/C and MDS 2710A/C/D
13
3.5 Data Interface Connections
The transceiver’s
DATA INTERFACE
connector is used to connect the
transceiver to an external DTE data terminal that supports the EIA-232
(formally RS-232) format. The transceiver supports asynchronous data
rates of up to 38400 bps. The data rate at the
DATA INTERFACE
connector
may differ from the data rate used over the air.
Table 4
lists each pin on the
DATA INTERFACE
connector and describes
its function.
Do not use a 25 wire (fully pinned) cable for connection to the
DATA
INTERFACE
connector. Use only the required pins for the application.
Damage may result if improper connections are made. Typical applica-
tions require the use of only Pins 1 through 8 for EIA-232 signaling.
3.6 Using the Radio’s Sleep Mode
In some installations, such as at solar-powered sites, it may be necessary
to keep the transceiver’s power consumption to an absolute minimum.
This can be accomplished using the Sleep Mode. In this mode, power
consumption is reduced to less than 16 milliamperes (nominal).
Sleep mode can be enabled under RTU control by asserting a ground (or
EIA-232 low) on Pin 12 of the radio’s
DATA INTERFACE
connector.
When Pin 12 is opened (or an EIA-232 high is asserted), the radio will
be ready to receive data within 75 milliseconds.
All normal functions are suspended while the radio is in sleep mode. The
PWR
LED will be off, except for a quick flash every 5 seconds.
Sleep Mode Example
The following example describes Sleep Mode implementation in a typ-
ical system. Using this information, you should be able to configure a
system that will meet your own particular needs.
Example:
Suppose you need communications to each remote site only
once per hour. Program the RTU to raise an EIA-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 will allow each RTU to
be polled once per hour with a significant savings in power con-
sumption.
CAUTION
USE
ONLY REQUIRED
PINS
