YSI WaterLog Series, Owner'S Manual

Page: 85 / 174

Understanding Binary Data
The Self-Timed pseudo-binary transmission and all Random transmission formats use a 6-bit per
byte pseudo binary format. The following shows the byte format:
1 Byte Value:
BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0
Parity Always 1 DATA 5 DATA 4 DATA 3 DATA 2 DATA 1 DATA 0
3 Byte Value:
BYTE 3 BYTE 2 BYTE 1
23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
P 1 D
17 D
16 D
15 D
14 D
13 D
12 P 1 D
11 D
10 D
9 D
8 D
7 D
6 P 1 D
5 D
4 D
3 D
2 D
1 D
0
Bit 7 is used for parity and will be stripped off by the time the data is sent to the decoding
software. Bit 6 is always set to 1, forcing the data byte to always be a printable character in the
ASCII table. Valid characters along with their weighted values are listed below in the GOES
Pseudo-Binary Look-up Table.
The GOES system supports 1, 2, 3, and 4 byte values with 6, 12, 18, and 24-bit precision
respectfully. The System 5000 uses 3 bytes (18 bits), by default, for Task data values. The
TM
appended battery voltage uses a single byte (6 bits). Date and time also use only one byte each
for seconds, minutes, hours, day, and month. However, date and time are seldom transmitted
through the GOES system, and if so, mainly for testing purposes.
System 5000
Outputs 6-27
TM