Rockwell Automation 1771-DMC_DMC1_DMC4_DXPS Control Coprocessor User Manual User Manual

Page 58

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Chapter 4

Using the Programming Environment

4-6

The following example program—HELLO.BAS—is the BASIC version of
the C example program.

rem hello.bas

rem ********************************************************************

rem

rem This program is used as an example so you can learn the mechanics

rem of writing a Basic program using the control coprocessor.

rem

rem ********************************************************************

rem Declare some variables to be used later in the program.

DIM total, x, y: INTEGER

rem Send the ASCII control code “[2J” to clear the screen.

PRINT CHR$(27); “[2J”

rem Print a text string to the screen.

PRINT “Hello, world!”

PRINT

PRINT

rem Now try some math with the variables declared at the beginning.

x = 2

y = 5

total = x + y

PRINT “The results of our math test (x + y) is ”; total

PRINT

This section shows a C program called CAT.C. It reads files from the
RAM disk and displays them to the screen; it is a simplified version of the
UNIX utility—

cat

—which concatenates files to standard output.

Figure 4.8 shows the output from the program CAT.C. The text displayed
is the concatenation of two files—HOSTS and HOSTS.EQUIV.

Figure 4.8

Access RAM Disk and Read File to Screen

Use an Example Application

Program to Access the

RAM Disk

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