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How does it work
CI-V
Radio
USB
CI-V
CPU
Tuner / Stepper IR
Router
PW-1
The heart of the CI-V router is an Atmel microprocessor on a Arduino Mega 2560 board. It is a
stand alone 16 MIP computer that runs a program that is located in it's internal 256K of flash
memory. The key feature of this processor is that it has four hardware serial ports. It is capable of
listening to and send to four serial ports at the same time without missing a byte. One of these ports
is connected to the USB interface, that is used for communications to a host processor. The other
three ports have an interface to the Icom CI-V bus.
The CI-V router is a "store and forward" message router. On the Icom CI-V bus, Icom messages
are sent. These messages are typically ten bytes in length and contains a source and destination
"ID" that is a byte long. The Icom messages also has a start two byte sequence and an end byte,
but it does contain any CRC or check sum that can be used to check the content. The router looks
for an icom message at each port. If one is identified, it does a sanity check that is rule based driven
from the message type. The router keeps track of which IDs are on each port in a table. The
destination address is read off of each incoming message. If the ID is in the destination table, the
router will direct the message to that port. If the destination ID is not in the table, the message is
forwarded to all ports other than the one that it arrived on.
Note: If an Icom device is moved from one port to another, resetting the router is required.
If a device reports a frequency or mode/bandwidth message, it assumed to be a radio.
If the USB port or the computer does an inquiry of a devices frequency or mode/bandwidth and the
device ID matches a known radio, the processor will report the last known frequency to the
computer without asking the radio. It is therefore REQUIRED that the Icom radio to be operated in
"Transceive" mode.
To keep the PW-1 from asking for status, the processor will generate a "transceive" message giving
the current frequency for each radio every five seconds to any port which does not have a radio.
Multiple Icom devices maybe put on each CI-V port, but collisions can occur on each port. Do not
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