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MDS 4710/9710 I/O Guide
MDS 05-3305A01, Rev. B
BUFF [ON, OFF]
This command sets or displays the received data handling mode of the
radio. The command parameter is either
ON
or
OFF
. The default is
ON
.
The setting of this parameter affects the timing of how received RF data
is sent out the
INTERFACE
connector. Outgoing (transmitted) data is not
affected by this setting.
If data buffering is
OFF
, the radio operates with the lowest possible
average latency. Data bytes are thus sent out the
INTERFACE
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 intro-
duced into the outgoing data flow.
If data buffering is
ON
, the radio operates in seamless mode. Data bytes
will be sent over the air as quickly as possible, but the receiver buffers
(stores) 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.
Note that seamless mode (
BUFF ON
) is intended only for applications
where the transmitter’s baud rate is greater than or equal to the
receiver’s baud rate. Enforcement of this rule is left up to the user.
CKEY [ON–OFF]
The
CKEY
command enables or disables the continuously-keyed func-
tion of the radio. When
CKEY
is set to
ON
, the radio is continuously
keyed.
CTS [0–255]
The
CTS
(clear-to-send) command selects or displays the timer value
associated with the CTS line response. The command parameter ranges
from 0 to 255 milliseconds.
For DCE operation, the timer specifies how long to wait after the RTS
line goes high, before the radio asserts CTS and the DTE can transmit
the data. A CTS value of zero keys the radio and asserts the CTS line
immediately after the RTS line goes high.
For CTS Key operation (see
DEVICE
command), the timer specifies how
long to wait after asserting the CTS, before sending data out the
DATA
INTERFACE
port. A timer value of zero means that data will be sent out
the data port without imposing a key-up delay. (Other delays may be
present based on selected radio operating parameters.)
DATAKEY [ON, OFF]
The
DATAKEY
command enables or disables the ability of the radio to key
the transmitter as data is received at the
DATA INTERFACE
connector.
Asserting RTS keys the radio regardless of this command setting.
