September
2017
Sentinel V SC and RT Operation Manual
Page 258
EAR-Controlled Technology Subject to Restrictions Contained on the Cover Page.
BIT POSITIONS
BYTE
7
6
5
4
3
2
1
0
65
RTC HUNDREDTH
66
SPARE
See Table 38 for a description of the fields.
Figure 104.
Variable Leader Data Format
Variable Leader data refers to the dynamic Sentinel V ADCP data (from clocks/sensors) that change with
each ping. The Sentinel V ADCP always sends Variable Leader data as output data (LSBs first).
Table 38:
Variable Leader Data Format
Hex Digit
Binary
Byte
Field
Description
1-4
1,2
VID / Variable
Leader ID
Stores the Variable Leader identification word (80 00h).
5-8
3,4
Ens / Ensemble
Number
This field contains the sequential number of the ensemble to
which the data in the output buffer apply.
Scaling: LSD = 1 ensemble; Range = 1 to 65,535 ensembles
NOTE: The first ensemble collected is #1. At “rollover,” we have
the following sequence:
1 = ENSEMBLE NUMBER 1
↓
65535 = ENSEMBLE NUMBER 65,535 | ENSEMBLE
0 = ENSEMBLE NUMBER 65,536 | #MSB FIELD
1 = ENSEMBLE NUMBER 65,537 | (BYTE 12) INCR.
9,10
11,12
13,14
15,16
17,18
19,22
21,22
5
6
7
8
9
10
11
RTC Year
RTC Month
RTC Day
RTC Hour
RTC Minute
RTC Second
RTC Hundredths
These fields contain the time from the Sentinel V real-time clock
(RTC) that the current data ensemble began. The TS-command
(Set Real-Time Clock) initially sets the clock. The Sentinel V does
account for leap years.
23-24
12
Ensemble # MSB
This field increments each time the Ensemble Number field (bytes
3,4) “rolls over.” This allows ensembles up to 16,777,215. See
Ensemble Number field above.
