Comtech EF Data SDM-650B - Manual (Page 340)

Trojan Interface SDM-650B Satellite Modem
G–44 Rev. 5
G.6.4.5.17 Equipment Type
This command returns the equipment model number and M&C firmware version number.
Command: <add/ET_”cr”
Response: >add/ET_SDM650S_x.xxx”cr””lf”]
Where: x.xxx = M&C firmware version.