4 <command><SP><arg1><SP>...<argN><CR><LF>
7 command - alphanurmeric command name
8 argN - numeric argument (unsigned base 10, 0-65535)
10 Positive response format:
12 0<SP><arg1><SP>...<argN><CR><LF>
15 argN - numeric value (unsigned base 10, 0-65535)
17 Negative response format:
19 -N<SP>"<desc>"<CR><LF>
22 -N - numeric error code (negative number)
23 desc - verbose error description
25 # Write digital outputs (masked)
37 # Wait specified amount of milliseconds
41 # Return firmware major version, minor version and revision
63 < -1 "Unknown command"
67 < -2 "Required parameter missing"
71 < -3 "Too many parameters"
75 < -4 "Invalid parameter"
78 > <CTRL-C> or <CTRL-D>
82 To recover from a possibly unknown board status,
83 a client should begin the conversation by issuing
84 an attention sequence, eventually followed by a reset.