ProSoft Technology MVI56-BAS - Manual (Page 65)

MVI56-BAS ♦ ControlLogix Platform Using the Program Port (PRT1)
BASIC Module (DB/BAS Compatible) User Manual
ProSoft Technology, Inc. Page 65 of 234
December 13, 2011
5.10 Debugging a BASIC Program
This section describes the BASIC commands that help the user debug BASIC
code.
The
BRKPNT
command sets a program break point at the specified line. This
means that the BASIC program exits, allowing the user to check all variables.
Enter
BRKPNT
before running a program in order to enable the break point
command.
To continue program execution, use the
CONT
command.
Syntax:
BRKPNT [line number]
If the line number selected is zero, the
BRKPNT
command will be disabled.
The
SNGLSTP
command allows the program to exit at all lines. The program will
stop first at the initial line number defined in the
SNGLSTP
command.
To continue program execution, use the
CONT
command.
Syntax:
SNGLSTP [initial line number]
Error Recovery
Use the
ONERR
command to recover from an error during program execution.
When an error occurs the program execution will skip to the line specified by the
ONERR
command. Each error has an associated code which can be retrieved by
using the
ERRCODE
operator or the
XBY
function.
Definition of error codes generated with the
ONERR
command:
1 Missing "=" sign.
2 Bad or missing expression.
3 NOT USED.
4 Variable name too long.
5 Expected a variable, but did not find one.
6 Exceeded maximum number of variables.
7 Missing ")".
8 Missing "(".
9 Bad variable element number.
10 NOT USED.
11 Argument stack error.
12 Bad or missing operator in expression.
13 Too many operators in expression.
14 ELSE token found without prior IF token.
15 Invalid syntax.
16 Missing variable after "LET" token.
17 Missing quote.
18 Statement not terminated correctly.
19 Bad or missing line number
20 No line to return to after GOSUB.
21 Tried executing RUN while already in RUN mode.