The CANaerospace specification states that my datatype can be ACARH4 witch are 4 ASCII chars, this should be called 2x 2 Hexadecimal values. My datatype Number is 0x100 which is in the User Defined datatypes.
| H0 | H1 | H2 | H3 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|---|---|---|---|---|---|
NODE ID | DATATYPE | SERVICE CODE | MESSAGE CODE | M/K | Upper values | lower values | |||||
| 1104 | 0x100 | 0-255 | M | 7 | H | 5 | F | ||||
So if my radio was tuned to 126.95 Mhz I would call 0xvalue = tohex (number), twice. and therefor 7h = tohex (126) and 5f = tohex (95 ) and the MK field would get an M (Mhz).
Its Node-Id = 1104 (this value is pre-assigned for the most part, see page 43, in the book "NASA AGATE data bus, Interface specification for Airborne CAN applications".
The Plan:
Now that some of the how-to stuff is out of the way.
- It is time to build a red box for the radio, install the radio and the CAN module along with the dual RJ-45 board, and wire the Arduino to DB-25.1 power it up and test it via the USB port.
- At this time if all goes well I will wire DB-25.2 for the ARC-14050 connector to the Arduino. The next major hurdles are to integrate the two CAN modules and see if I can pass data between the two boxes at that time the Protocol Converter will only be acting as node-0 or a local controller.
- One of the last tests is to see if I can interrogate my Radio from my Controller and see if the Radio responds with a correct status message
