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[KB144]How to Increase the Number of Symbols in SCADA BASIC Programs and SCADA BASIC limitations

Tags: Scada Basic, Scripting

Scripting
14 years ago
By RM
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Applies to:

PcVue all versions.
While the basic content of this article remains valid, details may have changed since it was written.
Summary:

This article explains how to modify the limit of the number of symbols in SCADA BASIC programs.
Details:

SCADA BASIC uses PcVue internal resources called Symbols. Each program that is loaded needs such Symbols. (For more information, see the SCADA BASIC programming manual.)

An application might need more than the default setting for the maximum number of Symbols.

To increase the maximum for number of Symbols in SCADA BASIC programs, type the following line above the main function:

SYS MAXSYMBOLES = x;

where x is the new Symbol number. (The default value is 600.)

Note

From version 7.20a of PcVue, the default value for that maximum is 4,200 Symbols. The upper limit to which the maximum can be set is 5,000.

The symbols defined in PcVue’s Scada Basic include:

SUB: subroutine

FUNCTION: function

DIM: data type defines

TABLE: array type

CHAR: STR type

CONST: constant type

IDENT: an identifier using alphabet, underscore, point and dollar symbol, e.g. a program/script global or local variable, a PcVue’s variable and so on

For information :

SCADA Basic Limitations

Max size of programs

640 000 bytes

Max number of symbols

4 200 to 5000 

Max number of programs (global included)

60 

Max length of the STR

512 

Max number of arguments for verbs

18 

Max number of declares for DLL

50 

Max number of arguments for DLL

16 

Created on: 05 Nov 2010 Last update: 13 May 2024