Somerdata AROW Series, Additional Instructions For Installation And Operation, Page: 48 / 82

AROW Series
Data Diode
Installation and Operation 8-7
Control and Status message format
All AROW messages are 9 bytes long: the 1st byte is the "Start of
Message" marker, the 2nd byte is the read/write flag byte, the 3rd and
4th bytes are the register address, the 5th to 8th are the Data payload
bytes and the last byte is the End of message marker.
Message
field name SOM Rd_wr addr Data EOM
Number of
bits 8 8 16 32 8
value 0x53 0x00 for
read,
0x01 for
write Register
address Data 0x0d
Bytes are sent Least significant bit first.
Where a field is more than 8 bits, the MSbyte is sent first.
Registers that are not implemented will return all 1s in the data field.
Any message that doesn't conform to the format above will be ignored
and discarded.
Memory map
Address range Type
0x0000 to 0x0FFF
System control and status (0x0100-0x010F is
Non volatile)
0x1000 to 0x1FFF
TCP/IP stack (0x1000-0x100F is Non volatile)
0x2000 to 0x2FFF MAC core (0x2400-0x241F and 0x2700-0x270F
are non volatile)
0x3000 to 0xFFFF Reserved