file: autoimet_rec.html
07 Jul 2004

LOGR53 AUTOIMET Updated Record Format - Firmware Version AUTOIMET V3.xx

The firmware version 3.xx record format provides for storage of data at each 1 minute sample interval. 96 bytes binary are stored per record in fixed format. The new record format adds 32 bytes to the old version 2.xx format to provide storage for local GPS data. (Note that this may change in the future). Storage is based upon a 'C' language structure shown here: 

/* LOGR 96 byte partially packed data record structure for storage in FLASH */
struct LOGR_record
   {
   unsigned char hour;   /* time is not packed for ease of verifying */
   unsigned char min;
   unsigned char day;
   unsigned char mon;
   unsigned char year;   /* year is offset from 2000 (no good after year 2255 :-) */
   unsigned short record;   /* sequential record number from startup */
   unsigned char mux_parm;  /* which option parameter in this record */
   short we,wn;   /* wind speed m/sec */
                  /* (short)(we * 100) ==> +/- 327.67 m/s */
   unsigned short wsavg,wmax,wmin;      /* (ushort)(wsavg * 100) ==> 0 - 655.35 m/s */

   short vdavg,compass;  /* vane average degrees, last compass degrees */
                         /* (short)(vdavg * 10) ==> +/- 3276.7 degrees */

   unsigned short bp;   /* barometer millibars */
               /* (ushort)((bp - 900.0) * 100) ==> 900.00 - 1555.35 mbar */

   short rh;  /* humidity %, deg C */
              /* (short)(rh * 100) ==> +/- 327.67 %RH */
   unsigned short th;  /* (ushort)((th + 20.0) * 1000) ==> -20.000 to +45.535 degC */

   short sr;  /* short wave w/m^2 */
              /* (ushort)(sr * 10) ==> +/- 3276.7 w/m^2 */

   unsigned short dome,body;  /* long wave dome and body thermistors
                                 deg Kelvin, thermopile microvolts */
                              /* (ushort)(dome * 100) ==> 0 - 655.35 degK */
                              /* (ushort)(body * 100) ==> 0 - 655.35 degK */
   short tpile;               /* (short)(tpile * 10) ==> +/- 3276.7 microvolts */

   short lwflux;  /* lwr flux */
                  /* (short)(lwflux * 10) ==> +/-3276.7 w/m^2 */

   short prlev;  /* precipitation values */
                 /* (short)(prlev * 100) ==> +/-327.67 mm */

   unsigned short sct; /* SeaCat sea temp deg C */
                       /* (ushort)((sct + 5.0) * 1000) ==> -5.000 to +60.535 degC */
   unsigned short scc; /* SeaCat conductivity Siemens */
                       /* (ushort)(scc * 1000) ==> 0.000 to +6.5535 Siemens/meter */

   unsigned long opt_parm;     /* optional value indicated in rec_mux */
   unsigned long gps_time;     /* UNIX t_time value from NOAA-SEAS GPS bridge system */
   float latitude;             /* lat & lon from NOAA-SEAS GPS bridge system */
   float longitude;
                               /* all following values are for the local GPS */
   float lgps_time;
   unsigned char lgps_valid;  
   float lgps_latitude;
   unsigned char lgps_ns;
   float lgps_longitude;
   unsigned char lgps_ew;
   float lgps_speed;
   float lgps_heading;
   unsigned long lgps_date;

   unsigned char spare[7];       /* optional spare values */
   unsigned short used;         /* set to 0xA5A5 upon record write */
   };

OBSOLETE LOGR53 AUTOIMET Record Format - Firmware Version AUTOIMET V2.xx - 06 Sep 2002

The firmware version 2.xx record format provides for storage of data at each 1 minute sample interval. 64 bytes binary are stored per record in fixed format. (Note that this may change in the future). Storage is based upon a 'C' language structure shown here: 2


/* LOGR 64 byte packed data record structure for storage in FLASH */
struct LOGR_record
   {
   unsigned char hour;   /* time is not packed for ease of verifying */
   unsigned char min;
   unsigned char day;
   unsigned char mon;
   unsigned char year;   /* year is offset from 2000 (no good after year 2255 :-) */
   unsigned short record;   /* sequential record number from startup */
   unsigned char mux_parm;  /* which option parameter in this record */
   short we,wn;   /* wind speed m/sec */
                  /* (short)(we * 100) ==> +/- 327.67 m/s */
                  /* (short)(wn * 100) ==> +/- 327.67 m/s */
   unsigned short wsavg,wmax,wmin;      /* (ushort)(wsavg * 100) ==> 0 - 655.35 m/s */
                                        /* (ushort)(wmax * 100) ==> 0 - 655.35 m/s */
                                        /* (ushort)(wmin * 100) ==> 0 - 655.35 m/s */
   short vdavg,compass;  /* last vane degrees, last compass degrees */
                         /* (short)(vdavg * 10) ==> +/- 3276.7 degrees */
                         /* (short)(compass * 10) ==> +/- 3276.7 degrees */

   unsigned short bp;   /* barometer millibars (converted from psi - Heise barometer) */
               /* (ushort)((bp - 900.0) * 100) ==> 900.00 - 1555.35 mbar */

   short rh;  /* humidity %, deg C */
              /* (short)(rh * 100) ==> +/- 327.67 %RH */
   unsigned short th;  /* (ushort)((th + 20.0) * 1000) ==> -20.000 to +45.535 degC */

   unsigned short ta;  /* air temp deg C */
                       /* (ushort)((ta + 20.0) * 1000) ==> -20.000 to +45.535 degC */

   short sr;  /* short wave w/m^2 */
              /* (ushort)(sr * 10) ==> +/- 3276.7 w/m^2 */

   unsigned short dome,body;  /* long wave dome and body thermistors
                                 deg Kelvin, thermopile microvolts */
                              /* (ushort)(dome * 100) ==> 0 - 655.35 degK */
                              /* (ushort)(body * 100) ==> 0 - 655.35 degK */
   short tpile;               /* (short)(tpile * 10) ==> +/- 3276.7 microvolts */

   short lwflux;  /* lwr flux */
                  /* (short)(lwflux * 10) ==> +/-3276.7 w/m^2 */

   short prlev;  /* precipitation values */
                 /* (short)(prlev * 100) ==> +/-327.67 mm */

   unsigned short sct; /* SBE48 sea temp deg C */
                       /* (ushort)((sct + 5.0) * 1000) ==> -5.000 to +60.535 degC */
   unsigned short scc; /* SeaCat conductivity Siemens - NOT USED */
                       /* (ushort)(scc * 1000) ==> 0.000 to +6.5535 Siemens/meter */

   unsigned long opt_parm;     /* optional value indicated in rec_mux */
   unsigned long gps_time;     /* UNIX t_time value from NOAA-SEAS GPS bridge system */
   float latitude;             /* lat & lon from NOAA-SEAS GPS bridge system */
   float longitude;
   unsigned short spare;       /* optional spare value */
   unsigned short used;        /* set to 0xA5A5 upon record write */
   };
Records may be dumped via XMODE command (very slow!) or by directly reading the removable FLASH storage card in a Linux-based PC.

A typical 64 byte binary record looks something like this (in HEX-ASCII):

0A222D150707CE01........841A0604FE0C3E247F4500F07F45A5A5

Wow! So now what!

First, note the following:
All integers are 2 bytes, stored MS byte first.

From the structures above, note that time is stored first, so:


TIME:
Bytes 0 - 4

0A22150700 is time as follows:


SEQUENTIAL RECORD NUMBER:
Bytes 5,6

A sequential record number is kept from power up - possibly useful for untangling problem data records with bad time ?? (may be eliminated in future software versions)


MUX'ED PARAMETER NUMBER (more detail later...):
Byte 7

DATA VALUES (more detail later...):
Bytes 8 - 61

Refer to the 'C' structure above for position and packing of each 2-byte integer data value (remember, MS byte first)


USED TAG
Bytes 62 - 63

These bytes are used to indicate that a record in FLASH storage has been written by the LOGR53. It is used internally by the instrument firmware to, for example, determine the next available record location upon power-up. These bytes should always be A5A5h in a used record, and FFFFh in an unused portion of the FLASH card.