M4-CYG1UW-TSR-M-ENG_Iss11.docx
Cygnus UW-TSR Operating Manual
77
18.
Serial Data Format
The CygLink program is provided to automatically decode the
measurement data sent from the Gauge, and to provide a
calibrated display of the results. For users who want to display and
log the data using their own software, this section describes the
arrangement of the data sent from the Gauge.
Protocol
1.
Differential RS-422 line drivers [TX+, TX-]
2.
Unidirectional - Gauge is transmit only
3.
Eight Data bits, 1 Start bit, 1 Stop bit, No Parity; 2400
baud
4.
Four packets per second
5.
Valid-Reading
packet-length : 7 bytes
6.
No-Reading
packet-length
: 3 bytes
Valid-Reading packet arrangement:
7 byte sequence:
1 SOH [hex 01]
2 Status-byte
3 Data-byte 0
4 Data-byte 1
5 Data-byte 2
6 Data-byte 3
7 ETB [hex 17]
No-Reading packet arrangement:
3 byte sequence:
1 SOH [hex 01]
2 Status-byte
3 ETB [hex 17]
Interpreting the Readings sent from the Gauge:
Decimal Point
position
Decimal Point position is implied from the
combination of Range, Resolution, and
Units bits in the Status byte of each
