User's Manual

40 MDS 9810 Installation and Operation Guide MDS 05-3301A01, Rev. C
These node types are needed for repeater sub-networks and simplex
sub-networks where simplex frequencies are used. See the Net-
work-Wide Diagnostics System Handbook (05-3467A01) for an expla-
nation of these node types.
HOPTIME [XSHORT, 16, 20, 25, 32, SHORT, NORMAL, LONG]
The
HOPTIME command sets or displays the hop time setting. The com-
mand is one of eight keywords whose parameters and related efficien-
cies are shown in Table 7.
Although the default setting is
HOPTIME NORMAL, transmission effi-
ciency can usually be improved by using
HOPTIME LONG when message
sizes typically exceed 256 bytes. This is because there will be less fre-
quent channel hops when using this setting, contributing to a smoother
flow of transmitted data.
Normally,
HOPTIME NORMAL and LONG are the only settings required.
Other hoptimes can be used to customize performance based on SEND
count settings and payload data poll length.
The only time shorter settings (
SHORT through XSHORT) should be con-
sidered is when the message size is very small and strong interference
of a persistent nature is occurring on many frequencies. In these cases,
a shorter hop time may improve the chances of a message getting
through—but at the cost of reduced channel efficiency.
Changes to the
HOPTIME setting may only be made at the master radio.
(This is because the master radio establishes the hop time setting for the
entire network.) At remote radios, the hop time setting may be read
when the radio is in synchronization with the master, but it may not be
changed.
Table 7. Hoptime Parameters
Hop Time
Keyword
Time
per
Hop
Max.
Bytes
per Hop
Channel
Efficiency
XSHORT 10 ms 9 32.1%
16 16 ms 21 46.7%
20 20 ms 30 53.6%
25 25 ms 39 55.7%
32 32 ms 57 63.3%
SHORT 40 ms 72 64.3%
NORMAL 80 ms 162 72.0%
LONG 160 ms 336 74.5%