Microhard Systems P900 - Data Time to Live (Mesh); Secondary Hop Pattern; Number of Aloha Slots (Mesh); Number of Mesh Slots (Mesh)

© Microhard Systems Inc. Confidential 94
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Values (0 - 49)
6.0 Register/Command Reference
S206 (PP/PMP) Secondary Hop Pattern
This register, together with the Network ID and the Secondary Hop Zone,
determines the Secondary Hopping Pattern which a P900 Repeater will use to
synchronize and communicate with downstream units. The S106 (Primary Hop
Pattern) register must be set to the same value on each repeater/slave that is
downstream of this unit.
Values (1 - 65535)
S184 (MESH) Data Time to Live
65535
Data time to live in 10ms ticks. Used to age data in mesh networks. The default
is 65535 (never age).
Values (1-10)
S215 (MESH) Number of Mesh Sync Slots
1
This register defines the number of sync slots available in a Mesh Frame. The
valid range is 1 - 10, with a default of 1. In systems with many coordinators,
additional slots may be required to avoid collisions. Register S216 can also be
used to provide randomness in sending sync packets to avoid collisions.
S215 must be set to the same value for each modem on the network or the unit
will not synchronize.
Values (1-255)
S214 (MESH) Number of Aloha Slots
60
This register defines the number of aloha slots available in a Mesh Frame. A
slot is a set period of time required to transmit the shortest packet (RTS, CTS,
ACK).
Increasing the number of aloha slots allows more time for a modem to transmit
data during a Mesh Frame. The number of aloha slots directly impacts the hop
interval, the more aloha slots, the more time to transmit data, but also the
longer the system sits on a single frequency. Reducing the number of aloha
slots creates a shorter hop interval which results in a system more immune to
interference, but too short an interval may disable communication if devices do
not have time to transmit.
Values (1-100)
S216 (MESH) Mesh Sync Duty Cycle
3
Defines how often the coordinator transmits sync packets (1-100). After each
sync packet transmission the coordinator picks a random number from 1 to the
value in S216 and transmits the next packet in this slot. 1 - every sync slot, 2—
on average once every 1.5 slots, 3 - on average once every 2 slots etc.