VXI VT1422A - Manual (Page 127)

Programming the VT1422A for Data Acquisition and Control 125 Chapter 4
Defining C Language Algorithms
This section is an overview of how to write and download C algorithms into
the VT1422A's memory. It is assumed that the user has some programming
experience in C, but since the VT1422A's version of C is limited, just about
any experience with a programming language will suffice. See “Creating
and Running Algorithms” on page 181 for a complete discussion of the
VT1422A's C language algorithm functionality.
Arithmetic Operators: add + , subtract - , multiply * , divide /
Assignment Operator: =
Comparison Functions: less than < , less than or equal <= , greater than > ,
greater than or equal >= , equal to == , not equal to !=
Boolean Functions: and && or || , not !
Variables: scalars of type static float and single dimensioned arrays
of type static float limited to 1024 elements.
Constants:
32-bit decimal integer;
Dddd... where D and d are decimal digits but D is
not zero. No decimal point or exponent specified.
32-bit octal integer;
0oo... where 0 is a leading zero and o is an octal digit.
No decimal point or exponent specified.
32-bit hexadecimal integer;
0Xhhh... or 0xhhh... where h is a hex digit.
32-bit floating point; ddd. , ddd.ddd , ddde±dd , dddE±d , ddd.ddde±dd
or ddd.dddE±dd where d is a decimal digit.
Flow Control: conditional construct if(){ } else { }
Intrinsic Functions:
Return the absolute value;
abs( <expr> )
Return minimum; min( <expr1> , <expr2> )
Return maximum; max( <expr1> , <expr2> )
User defined function; <user_name> ( <expr> )
Write value to CVT element; writecvt( <expr> , <expr> )
Write value to FIFO buffer; writefifo( <expr> )
Write value to both CVT and FIFO; writeboth( <expr> , <expr> )
Note for
VXIplug&play users
While the following discussion of algorithm definition is useful for
plug&play users as regards the coding of an algorithm or global variable
definition, the method of generating an algorithm code and actually
downloading it to the VT1422A becomes much easier because of plug&play
VT1422A.exe Soft Front Panel program and hpe1422_downloadAlg(...)
plug&play driver function.
Using the SFP "Algorithm Panel," an algorithm can be created and tested
and then stored to a file. The hpe1422_downloadAlg(...) plug&play driver
function was created specifically to download algorithms from files into the
VT1422A as part of the application program.