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Technical support
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www.avalanwireless.com
User’s Manual
AW900R2-PAIR
Serial Port Settings
These settings must match the RS-232 device wired to the radio.
Baud Rate
Drop down menu providing 6 choices from 9600 Baud to 115,200 Baud (serial
data rate).
Data Bits
Selectable 7 or 8 data bits (8 is the most common choice)
Parity
Selectable among “none”, “even”, “odd”, “mark” or “space” (“none” is the
most common choice)
Stop Bits
Select 1 or 2 stop bits (2 is the most common choice)
Tuning Parameters
These affect the behavior of the RF packet transmissions relative to the
incoming serial data. We suggest leaving these at the default values unless
the nature of the serial data or the requirements of the protocol being used
demand otherwise.
Next Byte Delay
The amount of time the bus must be idle after the Minimum Packet Size has
expired before the radio sends everything in it’s serial buffer. Values of 00 to
10 may be chosen, with a default of 00. Each unit of time is the reciprocal of
the Baud Rate (e.g. 104 µs at 9600 Baud).
Minimum Packet Size
Expected packet size bytes. Values of 01 to 99 may be chosen, with a default
of 01. Packets smaller than this will wait to see if additional packets arrive
during this time window. If additional packets arrive, they will be combined
into a single transmission.
Maximum Packet Size
Maximum number of bytes per transmission. Values from one more than
the Minimum Packet Size to 768 may be chosen with a default of 024 bytes.
Packets larger than this size will be sent over the RF as fragments and reas-
sembled at the receiver radio.
8. Here is additional information about the tuning parameters. The data protocol
you are using may require certain groupings of the bytes or particular timing of the
information:
• If you want
minimum latency
so that data is received as soon as possible after
it is sent, select a Next Byte Delay of 00 and a Minimum Packet Size of 01.
• If you are sending
large blocks of data
, a Minimum Packet Size of 01 can cause
the AW900R2’s buffer to overflow and bytes will be lost. The value can be in-
creased to a maximum that depends on the Baud Rate, corresponding to about
5.3 milliseconds:
Baud Rate
Largest Minimum Packet Size
9600
5
19200
10
38400
20
57600
30
76800
40
115200
60
