Furuno FCR-2107 Series Operator's Manual page 522

Appendix 5: Digital Interface
TLB - Target label
$--TLB,x.x,c--c,x.x,c--c,......x.x,c--c*hh<CR><LF>
| | | |
| | | |
| | +----+--------+----+------ 3
| +------------------------------ 2
+----------------------------------- 1
1. Target number 'n' reported by the device
2. Label assigned to target 'n'
3. Additional label pairs
4. Checksum
TTD - Tracked target data
$--TTD,hh,hh.x,s--s,a,x*hh<CR><LF>
| | | | |
| | | | +----- 5
| | | +------- 4
| | +------- 3
| +----- 2
+-----1
1. Total hex number of sentences need to transfer the messages
2. Hex sentence number, 1 to FF
3. Sequential message identifier, 0 to 9
4. Encapsulated tracked target data
5. Number of fill bits, 0 to 5
AP-70
| | |
| | +--- 4