Rockwell Automation 1771-DB BASIC MODULE - Manual (Page 136)

Chapter
Commands 10
10 -6
If software handshaking is enabled on the program port (page 2 -4), use
the Ctrl + S command to interrupt the scrolling of a BASIC program
during the execution of a LIST command. Ctrl + S stops output from
the transmitting port if you are running a program. In this case XOFF
Ctrl
+ S operates as follows:
XOFF only operates on PRINT statements (page 11 -29).
When received during a PRINT, data output is suspended immediately,
but program execution continues until the buffer is full and then the
program is suspended.
When received at any other time, the program continues until
encountering a PRINT statement. At this time data output is suspended.
The program continues to fill the output buffer until the buffer is full
and then the program is suspended.
XON Ctrl
+ Q (page 10 -5 ) resumes data output operation.
Important: Ctrl
+ S only works if you have enabled software
handshaking on the program port. You enable software handshaking
through the MODE statement (page 11 -20). Software handshaking is
enabled by default.
Syntax
Ctrl
+ S
Example
>10 A = 1
>20 DO
Ctrl
+ S
.
.
.
Ctrl
+ Q
>30 A = A+1
>40 PRINT A
>50 WHILE A < 20
READY
In this example, the output is suspended when Ctrl
+ S is pressed.
The output is continued after Ctrl
+ Q is pressed.
CTRL-S