Fluke user manual 2620A/2625A, Figure E-3. Example

2620A/2625A

Users Manual

/* Globals	convert() uses for destination		*/
int timestamp[6];		/* Scan timestamp	*/
int misc[3];		/* Temperature units, measurement rate, digital I/O */
float values[22];		/* Measurement values */
extern int	isnan();	/* Floating point	value is NaN (not a number) */
extern int	isinf();	/* Floating point	value is Inf (infinity) */

/*

-* main(): LOG_BIN? query response example program

**

**Converts a hard-coded LOG_BIN? response string into usable data.

*/

main()
{
extern int decode();		/* ASCII to binary decoding */
extern void convert();		/* Convert Hydra binary to usable types */
/*	Canned response for three channels: channel 1 is OTC, channel 5 is */
/*	OL and channel 10 is 1.0; remaining encoded data described below		*/
/*	(note that you can not determine the channel number, measurement		*/
/*	units, or measurement range, from this string; you must keep track */
/*	of that elsewhere)		*/

char *log_bin_response = "42@Y40BA00oo000007o0001oP000?h000";

/* Place to temporarily store raw data; 100 bytes is more than enough */

/* for any LOG_BIN? response string*/ unsigned char raw_data[100];

/* Decode string into raw data, then convert raw data into usable data */ convert(raw_data, decode(raw_data, log_bin_response));

/* Above global variables now usable; check example LOG_BIN? data */
/* against expected values					*/
if ((timestamp[0]	==	10) &&	/*	Hours	*/
(timestamp[1]	==	24) &&	/*	Minutes	*/
(timestamp[2]	==	29) &&	/*	Seconds	*/
(timestamp[3]	==	10) &&	/*	Month	*/
(timestamp[4]	==	4) &&	/*	Day	*/
(timestamp[5]	==	91) &&	/*	Year	*/
(misc[0]	==	0) &&	/*	Temp units and rate	*/
(misc[1]	==	15) &&	/*	Alarm outputs	*/
(misc[2]	==	255) &&	/*	Digital I/O	*/
(values[0]	== 0.0) &&		/*	Totalizer	*/
isnan(values[1])		&&	/*	Channel 1 data	*/
isinf(values[2])		&&	/*	Channel 5 data	*/
(values[3]	==	1.0)) {	/*	Channel 10 data	*/
printf("Conversion worked\n");
}
else {
printf("ERROR: conversion did not succeed!\n");
}
exit(0);
}
/* If your math library supplies alternatives to isnan() or isinf(), */
/* use them instead!					*/
int
isnan(f)
float f;
{
/* This is not portable, or completely				accurate (since NaN	mantissa	*/
/* must only be non-zero, and the sign				bit can be set), but this works */
/* for NaN values	returned by Hydra					*/

/* Compiler was free to promote to double */ float ff = f;

return ((*(unsigned long *)&ff) == 0x7fc00000L);

}

int isinf(f)

float f;

{

/* Again, this is not portable, but this time it is accurate */

/* Compiler was free to promote to double */ float ff = f;

return ((*(unsigned long *)&ff) == 0x7f800000L) ((*(unsigned long *)&ff) == 0xff800000L);

}

Figure E-3. Example

E-6