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Arrays, Arrays -10 – Sensaphone SCADA 3000 Users manual User Manual

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16-10

SCADA 3000 User’s Manual

WRITE_REC FUNCTION - used to write a single DataLog record to the DataLogger.

Summary:

write_rec();

Description
The write_rec function is used to write a single DataLog record to the DataLogger. All values

selected for logging on the DataLogger programming form will be logged once when this

function executes, regardless of whether or not the DataLogger is actually running or not. This

function is useful for event driven datalogging functions such as when an I/O point goes out

of range or when an alarm exists. Do not allow this function to execute continuously or large

amounts of data will accumulate in the datalogger. Also, do not allow this function to execute

more often than once a second because the DataLogger can only resolve timestamps to the

nearest second and will throw out records with identical time stamps.

Example:

/* This program will write a datalog record once per minute */

/* if input 0 is greater than 100 */

int last_minute;

main ()

{

if (read_uaf(input,0,0)>100.0) /* if input 0 is greater than

100*/

{

if (minutes != last_minute) /* is it a new minute? */

{

write_rec();

/* then write a datalog record

*/

last_minute=minutes;

/* reset minute check */

}

}

}

/*

End

of

program

*/

ARRAYS

Arrays allow you to store a lot of related information in a convenient, organized fashion. An

array lets you use one line of programming to create a series of variables. These variables share

the same basic name and are distinguished from one another by a numerical tag.

Example:

float count[10];

This means that an array named count has 10 members or “elements”, with each element hav-

ing its own value, starting with 0 and ending with 9. The first element is count[0], the second

element is count[1], and so on up to count[9]. The type float means that the actual numerical

value of each element is a float.

Example:

count[2] = 2.45

count[4] = 55000

count[9] = -200000