Basic programming guide – Remote Processing BASIC for the CX-10 Modbus User Manual

Page 74

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BASIC PROGRAMMING GUIDE

2-65

STRING

Syntax:

STRING total bytes,string length
Where: total bytes = total number of bytes in memory to allocate

string length = maximum number of bytes in a string

Function:

Allocate memory for strings

Mode:

Command, run

Use:

STRING 56,10 : REM Allocate memory for 5 10-byte strings

DESCRIPTION

Prior to using strings, you must use STRING to allocate memory for them. The STRING argument values are
computed by this equation:

total bytes = ((string length + 1) * number_of_strings) +1

The only way to recover string memory is with a "STRING 0,0" instruction. String memory is reclaimed and
then reallocated each time you use the STRING operator. Strings are terminated with a carriage return (0DH
or 13) which is the additional byte added to your bytes per string expr.

WARNING:

STRING causes BASIC-52 to execute the equivalent of a CLEAR instruction since string and numeric
variables occupy the same memory space. In other words, the STRING instruction clears all variables,
interrupts and stacks. Allocate string memory early in your program and don't reallocate it unless you can
accept the loss of all variables.

RELATED

ASC, CHR

ERRORS

MEMORY ALLOCATION

Memory not allocated for strings

C-STACK

STRING used in a subroutine, clearing the stack.

EXAMPLES

10

STRING 1000,40

20

$(0) = "Up to 40 characters in this string"

.
.
100

$(2) = COM$(1)

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