file: logr_testbed_rec.html

MET TESTBED53 Record Format - Firmware Version 4.11X or later - 07 Mar 2017

The current record format provides for storage of data at each 1 minute sample interval. 176 bytes binary are currently stored per record in fixed format.
Storage is based upon a 'C' language structure shown here: 


/* structure for minute data holds time, test type, and 10 x 4 array of parameter values
	for ASIMET modules under test - 176 bytes total */
struct TEST_record
	{
	unsigned char hour;
	unsigned char min;
	unsigned char day;
	unsigned char mon;
	unsigned short year;
	char test_type[8];	/* set to HRHPRC, WNDBPR, LWRSWR */
	float module_data[10][4]; /* 10 sets of module data; 5 of each module type 
					indicated by test_type[] - 240 bytes */
	unsigned short used;         /* set to 0xA5A5 upon record write */
	};
Records may be dumped via XMODE command (very slow!) or by directly reading the Compact FLASH storage card on a PC.

A typical 176 byte binary record looks something like this (in HEX-ASCII):

0A22060307E1485248505243418A4BC7........41ABB22DA5A5

Wow! So now what!

First, note the following:
All short integers are 2 bytes, stored MS byte first.
All floats are IEEE 4-byte in big-endian order

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


TIME:
Bytes 0 - 4

0A22150700 is time as follows:


TEST TYPE:
Bytes 6-11

This will be ASCII for HRHPRC, LWRSWR, or WNDBPR to indicate which test the logger was setup for.


DATA VALUES (more detail later...):
Bytes 12 - 173

Refer to the 'C' structure above for position of each 4-byte IEEE float data value (big-endian order)


USED TAG
Bytes 174 - 175

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.