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Notes:
1. Host does not send a NAK if it gets a bad response. Host should flag it as a communications
error or firmware version issue.
2. The NAK indicates the location of the first problem detected. It is possible for the slave to
process part of a message properly and still return a NAK for one or more invalid data fields.
For example, it would be possible for a slave to receive a setup command and process the
current setting but not the voltage setting if the voltage setting were out of range or improperly
formatted. In this case the slave would return a NAK message indicating the first field with a
problem.
3. The bad field number indicates which field was determined to be a problem. Fields are
separated by commas. Field number 1
is the header. In the message “@01.1a1#2,1,0,12345”
field number 3 has a value of ‘0’
4. The slave does not sent a NAK if the command was directed to the global unit address (00).
5. The slave does not send a NAK if it is unable to decode the unit address from the message.
6. The slave does not send a NAK if the CRC is enabled and the transmitted CRC does not match
the slave calculated CRC for the message.