Rockwell Automation 1771-DB Basic Module User Manual - Series A - Manual (Page 46)

Operating Functions
Chapter 5
5–9
Action taken: When you enter NEW(cr),
the BASIC Module deletes
the program that
is currently stored in RAM memory. In addition, all
variables are set equal to ZERO, all strings and all BASIC evoked
interrupts
are cleared. The REAL TIME CLOCK, string allocation, and
the internal stack pointer values are not affected.
In general, NEW (cr) is
used to erase a program and
all variables.
Action taken: The NULL[integer] command
determines how many
NULL characters
(00H) the BASIC Module outputs after a carriage
return. After initialization NULL 0.
Most printers contain a RAM
buffer that eliminates the need to output NULL characters
after a carriage
return.
Action taken: This command stops
execution of the current program and
returns the BASIC Module
to the COMMAND mode. In some cases
you can continue
execution using a CONTinue. See the explanation
for CONTinue for more information.
5.3.7.1
Command: Disabling Control C
Action taken: This command disables
the Control C break function.
You can
do this by setting bit 48 (30H) to 1. Bit 48 is located in
internal memory location 38 (26H). Set bit 48 by executing the following
statement in a BASIC Module program or from the
command mode:
DBY(38)
DBY(38).OR.01H
When bit
48 is set to 1, the Control C break function for both LIST and
RUN operations
is disabled. Cycling power returns Control C to normal
operation
if it is disabled from the command mode.
To re-enable the Control
C function, execute the following statement in a
BASIC Module
program or from the command mode.
DBY(38)
DBY(38).AND.0FEH
CALL routines
do not check for this feature. If you enter a Control C
while
using a CALL routine, the program stops if Control C is enabled or
disabled.
5.3.5
Command: NEW
5.3.6
Command: NULL [integer]
5.3.7
Command: Control C