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9. The slave response delimiter text is shown in the right most column in the command tables.
This text is what the unit will return as a delimiter if enabled with the “i” command. Delimiter
text is mainly used for troubleshooting as an easier way to manually decode fields.
There is no
requirement for the host (master) to send delimiter text if delimiter text is enabled. The host can send
delimiter text whether or not delimiter text is enabled.
10. Commands are variable length.
11. Commands have a CRC for error checking at the end of the command. The CRC is calculated
from all the ascii characters, starting with the sync and ending with the comma before the CRC
value. See section
B.1.7
for a CRC calculation example.
12. Out of range or invalid values received by a slave returns a NAK. When a NAK is returned it
indicates where there was a problem detected. It is possible for part of a command to be
processed and acted on even though one data field was determined to be invalid and a NAK is
returned. The NAK message indicates where the first error was detected. If an ACK is
returned then all portions of the command were determined to be valid and were processed.
See the NAK command, section
B.1.9.
13. A NAK response is not returned by a slave if the CRC is enabled and the slave determines that
the CRC was incorrect. Slaves will not respond to commands with invalid CRC values (if the
CRC is enabled).
14. Commands are terminated by carriage return (0x0D) and line feed (0x0A).
15. Any chars between a CR-LF and @ are ignored.
16. This protocol is fully text-editor compatible.
17. Scientific notation is not allowed (i.e. 7.65e2 or 4.56E-1 are not allowed).
18. Signed numbers are allowed when the field in the message is signed. A positive number is
implied and does not need a ‘+’ sign. Negative numbers are preceeded with a ‘-‘.
19.
The ‘no response’ time-out duration the host (master) uses should not be less than 20ms in
order for the Diamond controller to have enough time to process commands. Commands that
write to non-
volatile memory (such as the “w” command) could require significantly longer time-
out durations. Commands that require longer time-out durations will be indicated in the
command description.
20. The maximum length of any message (including text delimiters) should not exceed 1024
characters. Messages longer than 1024 bytes will result in a NAK response from the slave.
21. Slaves will not send a response to messages directed to the global address (device address
00). All slaves on the network will perform the requested action if they properly receive the
command, however no response is sent.
B.1.5 Unit Addressing (@AA.a)
Unit ID ‘AA’ Channel
ID ‘a’
Description
00
0
Directed to all channels on all units
