User Manual

MHX-2400 Operating Manual: Chapter 3 Configuration Options 29
FCC Regulations
The hopping interval is
controlled by the master.
The slave and repeater units
will use the hopping interval
setting from the master.
Warning: Communication will
fail if the hopping interval is not
set according to the guidelines of
Appendix E.;..
IMPORTANT:
FCC Regulations allow up to 36 dBi effective radiated power (ERP).
Therefore, the sum of the transmitted power (in dBm), the cabling loss
and the antenna gain cannot exceed 36 dBi.
1 mW = 0 dBm
10 mW = 10 dBm
100 mW = 20 dBm
1000 mW = 30 dBm
For example, when transmitting 1 Watt (30 dBm), the antenna gain
cannot exceed 36 - 30 = 6 dBi.
Microhard Systems Inc. limits the MHX-2400’s transmitted power to
100mW for all units purchased with antennas with gain above 6dBi.
S Register 109 - Hopping Interval
This option determines the frequency at which the modems change channel.
Note that the Master controls this parameter for the entire network. This
setting is ignored in units configured as Slaves or Repeaters.
The allowable settings are:
1 8 msec
2 12 msec
3 16 msec
4 20 msec
5 30 msec
6 45 msec
7 80 msec
*8 120 msec
Some of the shorter hop intervals are incompatible in combination with:
• repeaters in the system;
• the value set for link rate (S103); and,
• larger maximum packet sizes (S112).
See Appendix E for optimal Hopping Interval settings in relation to packet
size and link rate.