MDS 05-3628A01, Rev. B
MDS 4790M (MPT 1411) I/O Guide
57
To dekey the transmitter, press ENTER, then use the up/down arrow buttons to
select DISABLE (manual dekeying). Press ENTER again to dekey the transmitter.
Unit Address
This screen displays the radio’s unit address, which uniquely identifies a single
radio within a network. It is used primarily for diagnostics.
When the radio first powers up, unit address is unprogrammed. Unit address can
range from 0...65000, but can only be manually programmed from 10000...65000.
(Addresses in the 0...9999 range only occur when they are assigned as default
values following factory programming of the serial number.).
Key On Data
This screen is used to set or display the radio’s keying mode (key-on-data, or
key-on-RTS). In key-on-data mode, the radio will automatically key itself whenever
input data arrives on the DB-25 port. In key-on-RTS mode, the radio will only key
in response to an RTS or PTT signal.
To set the radio to key-on-data mode, press ENTER, then use the up/down arrow
buttons to select ENABLE. Press ENTER again to make the change. To set the
radio to key-on-RTS mode, press ENTER, then use the up/down arrow buttons to
select DISABLE. Press ENTER again to make the change.
Note that key-on-data mode is only applicable when the input data source is digital.
When the input data source is analog, this setting is irrelevant.
Data Buffering
This screen is used to enable or disable data buffering. If data buffering is enabled,
the radio operates in seamless mode, where the data is sent over the air as quickly
as possible. However, the receiver will buffer (hold) the data until enough bytes have
arrived to cover worst-case gaps in transmission. This mode of operation is required
for protocols such as MODBUS™ that do not allow gaps in their data transmission.
If data buffering is disabled, the radio operates with the lowest possible data
latency (average). Data bytes are sent out the data port as soon as an incoming
RF data frame is disassembled. Average and typical latency will both be below 10
ms, but idle character gaps may be introduced into the outgoing data flow.
To enable or disable data buffering, press ENTER, then use the up/down arrow
buttons to display ENABLE or DISABLE. Press ENTER again to make the change.
DLINK Baudrate
This screen is used to set or display the diagnostic baud rate. Allowable selections
are: 1200, 2400, 4800, 9600 and 19200 bps.
To change the setting, press ENTER, then use the up/down arrow buttons to
display the desired setting. Press ENTER again to make the change.
KEY command, page 35
DKEY command, page 33
Unit Address
2067
UNIT [10000–65000]
command, page 44
Key On Data
enabled
DATAKEY [ON/OFF] command
page 33
Data Buffering
enabled
BUFF [ON/OFF] command,
page 31
DLINK Baudrate
4800
