4RF Aprisa SR+, User Manual

Page: 152 / 492

152 | Managing the Radio
Aprisa SR+ User Manual 1.11.1
Mode
This parameter defines the mode of operation of the serial port. The default setting is Standard.
Option Function
Disabled The serial port is not required.
Standard The serial port is communicating with serial ports on other
stations.
Standard
(Streaming) This mode when used with a small MTU setting provides reduced
latency without introducing gaps in the serial stream by taking
exclusive control of the radio channel.
Bit Oriented This mode allows support for legacy protocols that are not
compatible with standard UARTs
(see ‘ Bit Oriented ’ on page 154).
Bit Oriented
(Streaming) This mode allows support for legacy protocols that are not
compatible with standard UARTs (
see ‘ Bit Oriented ’ on page 154).
It includes Streaming which when used with a small MTU setting
provides reduced latency without introducing gaps in the serial
stream by taking exclusive control of the radio channel.
Mirrored Bits ® Mirrored Bits® is a serial communications protocol used to
exchange internal logic status messages directly between relays
and devices used in line protection, remote control and
monitoring, relay remote tripping, sectionalizing and other such
applications. The protocol is often described as a relay-to-relay
communications technology.
Terminal Server A base station Ethernet port can communicate with both Ethernet
ports and serial ports on remote radios.
RS-232 traffic is encapsulated in IP
packets (see ‘ Serial > Port
Setup ’ Terminal Server on page 160).
SLIP IP packets are encapsulated over RS- 232 interface port (see ‘ Serial
> Port Setup ’ Serial Line Interface Protocol (SLIP) ’ on page 163).
MTU Size (bytes)
This parameter sets the size of the packet in bytes received before it is transmitted if an inter-frame gap is
not detected. Setting a smaller Maximum Transmission Unit (MTU) may reduce latency, but this should only
be done with streaming mode or else if serial protocol is known to allow gaps at the receiver. The default
setting is 512 bytes.
Baud Rate (bit/s)
This parameter sets the baud rate to 300, 600, 1200, 2400, 4800, 9600, 19200, 38400, 57600 or 115200 bit/s.
The default setting is 9600 bit/s.
Character Length (bits)
This parameter sets the character length to 7 or 8 bits. The default setting is 8 bits.