User's Manual

MDS 05-3301A01, Rev. C MDS 9810 Installation and Operation Guide 37
a = Data bits (7 or 8)
b = Parity (N for None, O for Odd, E for Even)
c = Stop bits (1 or 2)
The factory default setting is 4800 baud, 8 data bits, no parity, 1 stop bit
(Example:
4800 8N1).
NOTE: 7N1, 8O2, and 8E2 are invalid communication settings and are
not supported by the transceiver.
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 received data sent out
the
DATA INTERFACE connector. Data transmitted over the air by the
radio is unaffected by the
BUFF setting.
If data buffering is set to
OFF, the radio will operate with the lowest pos-
sible average latency. Data bytes are sent out the
DATA INTERFACE port
as soon as an incoming RF data frame is disassembled. Average and typ-
ical latency will both be below 10 ms, but idle character gaps may be
introduced into the outgoing data flow.
If data buffering is
ON, the radio will operate in a seamless mode. That
is, data bytes will be sent over the air as quickly as possible, but the
receiver will buffer the data until enough bytes have arrived to cover
worst case gaps in transmission. The delay introduced by data buffering
may range from 25 to 50 ms, but the radio will not create any gaps in the
output data stream. 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.
Changes to the
BUFF setting may only be made at the master radio. This
is because the master radio broadcasts the buffer setting for the entire
network. At remote radios, the buffer setting may be read when the radio
is in synchronization with the master, but it may not be changed.
CTS [0–255]
The
CTS (clear-to-send) command sets or displays the timer value asso-
ciated with the CTS line response. The command parameter ranges from
0 to 255 milliseconds.