AMX NETLINX PROGRAMMING LANGUAGE, Manual

Page: 22 / 246

NetLinx Programming Overview
6 NetLinx Programming Language Reference Guide
DEFINE_CALL (Subroutines)
Axcess Language NetLinx Language
Axcess provides two methods for incorporating sub-
routines into your program.
•
DEFINE_CALL
subroutines are defined in the
program and support parameter passing into the
call. Changing the parameter value inside the call
changes the value of the variable passed to the
parameter. The
DEFINE_CALL
can use global
variables or defined local variables.
DEFINE_CALL
is for standalone statements and
cannot be used in-line as an expression.
•
SYSTEM_CALL
is an externally defined subroutine
with a '.LIB' extension.
SYSTEM_CALL
programs
are produced by AMX and are available on
CD-ROM and on the Tech Support Web site at
www.amx.com.
DEFINE_CALL 'SWITCH' (CARD,IN,OUT)
{
SEND_STRING CARD,
"ITOA(IN),'*',ITOA(OUT),'!'"
}
DEFINE_CALL 'MULTIPLY' (X,Y,RESULT)
{
RESULT = X * Y
}
DEFINE_PROGRAM
PUSH[TP,11]
{
CALL 'SWITCH' (SWITCHER,4,1)
}
PUSH[TP,12]
{
CALL 'MULTIPLY' (3,4,VALUE)
}
SYSTEM_CALL [1] 'VCR1'
(VCR,TP,21,22,23,24,25,26,27,28,0)
Like Axcess, NetLinx supports
DEFINE_CALL
and
SYSTEM_CALL
. NetLinx also supports functions, which
are similar to a
DEFINE_CALL
(s). They can be used
standalone or in-line as an expression.
Functions are defined in the
DEFINE_CALL
section of
the code as a global function.
Defining a function differs slightly from a
DEFINE_CALL
:
• The data type of the function's return value must be
specified.
• The function name is not enclosed with quotes or case
sensitive.
DEFINE_CALL 'SWITCH' (CARD,IN,OUT)
{
SEND_STRING CARD,
"ITOA(IN),'*',ITOA(OUT),'!'"
}
DEFINE_FUNCTION INTEGER MULTIPLY
(INTEGER X, INTEGER Y)
{
RETURN (X * Y)
}
DEFINE_PROGRAM
PUSH[TP,11]
{
CALL 'SWITCH' (SWITCHER,4,1)
}
PUSH[TP,12]
{
VALUE = MULTIPLY(3, 4)
}
SYSTEM_CALL [1] 'VCR1'
(VCR,TP,21,22,23,24,25,26,27,28,0)