User Manual

MDS 05-4670A01, Rev. E SD Series Reference Manual (x710 Mode) 27
If data buffering is ON , the radio operates in seamless mode. Data bytes
are 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: 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 the user’s
responsibility.
CKEY [ON–OFF]
Key TX
Continuously
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
and the Timeout Timer is disabled.
CTS [0–255]
Clear-to-Send Time 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 from the DATA
INTERFACE port. A timer value of zero means that data will be sent from
the data port without imposing a key-up delay. (Other delays might be
present based on selected radio operating parameters.)
CTSHOLD [0–60000]
Clear-to-Send Hold
Time
Used in DEVICE CTS KEY mode, this command sets the amount of time in
milliseconds that CTS remains present after transmission of the last
character from the RXD pin of the DATA port. This “hold time” can be
used to prevent squelch tail data corruption when communicating with
other radios.
The CTSHOLD setting can range from 0 to 60000 ms (60 seconds). The
default value is 0, which means that CTS will drop immediately after the
last character is transmitted. If the command is entered when the radio
is in DEVICE DCE mode, the response CTSHOLD N/A is shown.