© Microhard Systems Inc.
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6.0 Configuration
Values
S110
Data Format
1 8N1
2 8N2
3 8E1
4 8O1
5 7N1
This register determines the format of the data on the
serial port.
The default is 8 data bits, No parity, and 1 Stop bit.
6 7N2
7 7E1
8 7O1
9 7E2
10 7O2
Values (bytes)
S112
Packet Max Size
1-255
255
Determines that maximum number of bytes from the
connected device that should be encapsulated into a
packet. Large packet sizes may produce the best data
throughput; however, a smaller packet is less likely to
become corrupted and, if it does, is retransmitted with a
lesser impact on network traffic. The default setting of
255 bytes is suited to most applications.
Values
0-254
5
S113
Packet Retransmissions
This register determines the maximum amount of times
that a packet will be retransmitted (in addition to the
initial transmission), noting the following specific
behaviors in various network topologies:
In a PMP system, set
S113 to the minimum
value
required
as,
effectively,
the
data
throughput from Master
to Remote is divided by 1
plus the number stored in
S113.
PMP:
Master will retransmit each data packet the exact number of times specified in
its S113; Slave will retransmit only if necessary, and then only until a given
packet is acknowledged or the value of the Slave’s S113 is reached.
PTP:
Modem will retransmit to its counterpart only if necessary, and to a maximum
number of the value in S113.
Values (Hop Intervals)
S115
Repeat Interval
1-255
3
S115 determines the number of slots which are
available within a window of opportunity for Remote
units to submit channel requests to the Master modem.
For a large number of remotes, the value of S115 should be set relatively high:
Remotes will randomly contend for the ability to access the channel request slots.
For a small number of Remotes, it is advisable to keep S115 closer to the default
value so as to not ‘waste bandwidth’ by maintaining a relatively large window housing
a greater-than-necessary number of channel reservation request slots.
In a TDMA-type system, S115 may be set to 1 as the Remotes are not able to
request a transmission channel: the Master polls each Remote for data.
If adjustment of S112 is
being contemplated, take
into consideration such
factors as data rate,
wireless link rate, and the
hop interval (S102, S103,
S109).
