SRT CS100, Installation And Operation Manual

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Configuration using proAtoN
Page 26
Channel 1 start slot
This is the slot number for the first transmission on channel 1. The slot number can range from -1 (transmission
disabled on this channel) to 2249. Note that each message #21 transmission occupies two slots and associated
base station slot reservations must therefore reserve two slots.
Channel 1 interval
This is the interval in slots between transmissions on channel 1. The interval can range from 0 to 3240000 slots,
which equates to an interval of one day. Typically the interval is set to 13500 slots (6 minutes) on each channel
which results in an overall interval of 3 minutes.
Channel 2 start UTC
This is the hour and minute for transmission on channel 2. This specifies the AIS frame (minute) within a day
in which the start slot for channel 2 resides. Typically the channel 2 start time is offset by 3 minutes from the
start time used for channel 1. With a 6 minute reporting interval on each channel this results in a transmission
every 3 minutes on alternating channels.
Channel 2 start slot
This is the slot number for the first transmission on channel 2. The slot number can range from -1 (transmission
disabled on this channel) to 2249. Note that each message #21 transmission occupies two slots and associated
base station slot reservations must therefore reserve two slots.
Channel 2 interval
This is the interval in slots between transmissions on channel 2. The interval can range from 0 to 3240000 slots,
which equates to an interval of one day. Typically the interval is set to 13500 slots (6 minutes) on each channel
which results in an overall interval of 3 minutes.
Example FATDMA schedule
A typical transmission schedule requires that the AIS AtoN transceiver transmit AIS message #21 every three
minutes on alternating channels. The transmission schedule is presented diagrammatically in Figure 12.
Figure 12 Example FATDMA schedule
This schedule can be configured using the following values:
● Channel 1 start UTC = 00:00 (the first frame of every hour)
● Channel 1 start slot = 0 (the first slot in the frame, so slots 0 and 1 are used by the message #21
transmission)
Channel 1
00:01 00:02 00:03 00:04 00:05 00:06 00:07 00:08 00:09 00:10 00:11 00:12 00:00
hh:mm
Channel 1 interval
13500 slots (6 minutes)
Channel 2
00:01 00:02 00:03 00:04 00:05 00:06 00:07 00:08 00:09 00:10 00:11 00:12 00:00
hh:mm
Channel 2 interval
13500 slots (6 minutes)
Overall interval
6750 slots
(3 minutes)