FOCUS Enhancements 3.2 - Manual (Page 171)

External Control Commands
157
Firefly Model Request (?X)
Command:
Requests the software version.
Format:
?X<CR>
Response:
<channels>V<softwarever><CR>
Explanation:
This command is always global specific.
Examples:
Command Response Meaning
?X <CR> 4V2.00<CR> 4 channels ver 2.00 software
?X <CR> 2V3.12 <CR> 2 channels ver 3.12 software