Sensaphone SCADA 3000 Users manual - Manual (Page 194)

16-8
SCADA 3000 User’s Manual
FUNCTION LIBRARY
In SCADA 3000’s C language there are five functions defined—Read, Write, Reset, Power, and
Write Record. These functions allow you to retrieve/assign certain values and incorporate them
into your C program. Most parameters within the SCADA 3000 are accessible via the UAF
(Universal Address Format). The Read and Write functions always include an associated UAF.
A function can be a statement by itself or it can be used to retrieve a value and return it.
READ FUNCTION - Used to read a value from the SCADA 3000 as described by its UAF.
Summary:
float read_uaf(t,g,e)
int t; UAF source type: input, output, timer, counter, bit,
ladder_variable,alarm,diagnostic
int g; UAF group number: 0-1023
int e; UAF element number: 0-255
Description
The read_uaf function returns the value of any UAF register that is specified by the three
parameters, The value of the specified UAF will always be returned by this function as a float
even if the real UAF register is an integer or bit. Note that there is no run time error checking
on this function. If a user requests an invalid register location, the function will not generate
an error, but will just return an invalid result.
RETURN VALUE - The read_uaf function returns the value of the specified UAF register.
Example:
float tank_high;
main ()
{
if (read_uaf(input,0,0)>100.0) /*If input 0 on main
board is greater than 100 */
{
tank_high=1; /* then set the tank_high
variable equal to one */
}
}
WRITE FUNCTION - Used to write a value to the SCADA 3000 as described by its UAF.
Summary:
float write_uaf(t,g,e,d)
int t; UAF source type: output, bit, ladder_variable,
c_variable, alarm
int g; UAF group number: 0-1023
int e; UAF element number: 0-255
int d; New data for UAF: “on,” “off,” floating point number
Description
The write_uaf function is for changing the value in any of the UAF registers. The parameters
of the function specify the location of the UAF register to be changed as well as the new value
for the register.
RETURN VALUE - The write_uaf function always returns a zero.