SMCA
The SMCA protocol is an NMEA 0183-compatible string used for connecting to helideck monitoring systems and other related systems.
Data:
Roll, pitch
Heave
Surge, sway
Format:
$PSMCA,±xx.xxx,±yy.yyy,±hh.hh,±ss.ss,±ww.ww<CR><LF>
SMCA protocol description | |||||
|---|---|---|---|---|---|
FIELD N. | FIELD | DESCRIPTION | UNIT | TYPE | NOTE |
0 | $PSMCA | identifier | - | string | Telegram identifier. |
1 | ±xx.xxx | roll angle | [deg] | DBL | sign: positive (+) is port up, negative (-) is port down. xx.xxx: ‘xx' is the integer part of the roll represented by two digits in range [-99,99], ‘.’ is decimal separator and 'xxx’ is the fractional part of the roll represented by three positive digits in range [0,999]. |
2 | ±yy.yyy | pitch angle | [deg] | DBL | sign: positive (+) is bow down, negative is (-) bow up. yy.yyy: ‘xx' is the integer part of the pitch represented by two digits in range [-99,99], ‘.’ is decimal separator and 'xxx’ is the fractional part of the pitch represented by three positive digits in range [0,999]. |
3 | ±hh.hh | heave | [m] | DBL | sign: positive (+) is upward w.r.t reference plane, negative (-) is downward w.r.t reference plane. hh.hh: ‘hh' is the integer part of the heave represented by two digits in range [-99,99], ‘.’ is decimal separator and 'hh’ is the fractional part of the heave represented by three positive digits in range [0,99]. |
4 | ±ss.ss | surge | [m] | DBL | sign: positive (+) is forward (bow direction), negative (-) is backward (stern direction). ss.ss: ‘ss' is the integer part of the surge represented by two digits in range [-99,99], ‘.’ is decimal separator and 'ss’ is the fractional part of the surge represented by three positive digits in range [0,99]. |
5 | ±ww.ww | sway | [m] | DBL | sign: positive (+) is starboard right, negative (-) is port left. ww.ww: ‘ww' is the integer part of the sway represented by two digits in range [-99,99], ‘.’ is decimal separator and 'ww’ is the fractional part of the sway represented by three positive digits in range [0,99]. |
Example:
SMCA frame with raw example data is listed below.
$PSMCA,+00.060,-02.513,+00.01,+01.86,-00.79<CR><LF>
Field 0 | Field 1 | Field 2 | Field 3 | Field 4 | Field 5 |
|---|---|---|---|---|---|
$PSMCA | +00.060 | -02.513 | +00.01 | +01.86 | -00.79 |
Decoded values:
Roll
Raw value: +00.060, decoded roll angle: 0.06 degrees
Pitch
Raw value: -02.513, decoded pitch angle: -2.513 degrees
Heave
Raw value: +00.01, decoded heave: 0.01 meters
Surge
Raw value: +01.86, decoded surge: 1.86 meters
Sway
Raw value: -00.79, decoded sway: -0.79 meters
Note 1
The fields of data (e.g., ‘xx.xxx’) are decimal numbers with leading zeroes where appropriate.
Note 2
The reference frame for data (e.g., roll) is configurable in the SMCA protocol. Also, the data's location (e.g., MRU or MP1) is configurable.