All data on the fastnet bus is sent from a node adress, and possibly send to a node (or to all nodes through the 0xFF broadcast address)

Collective addresses (hex)

FA     All 20/20s  
FB     All Halcyon FFDs  
FC     All Pilot FFDs  
FD     All Processor Nodes  
FE     All FFDs  
FF     Entire System

Individual addresses (hex, decimal, description)

01  01 Normal CPU (depth board in H2000)
05  05 Normal CPU (wind board in H2000)
09  09 Performance processor

0D  13 Expansion unit  (0D to 0F)

0F  15 Halcyon Gyro through Gyro processor
10  16 Halcyon 2000 Compass connected directly to FastNet bus
12  18 Halcyon Gyro-Stabilised Compass connected to Pilot ACP (sometimes also 11 hex)

20  32 FFD's (20 to 2F)

30  48 Halcyon FFD's (30 to 3F)

40  64 Display 20/20 (40 to 4F)

50  80 Pilot FFD (50 to 5F)

60  96 External compass interfaced via NMEA FFD (60 to 6F)

112  274 Load cell amplifiers (112 to 127 hex)

128  296  Tank level sensor