Publication 1766-RM001A-EN-P - October 2008
384
ASCII Instructions
Instruction Operation
When the rung goes from false-to-true, the Enable bit (EN) is set. When
the instruction is placed in the ASCII queue, the Queue bit (EU) is set. The
Running bit (RN) is set when the instruction is executing. The DN bit is set
on completion of the instruction.
Once the requested number of characters are in the buffer, the characters
are moved to the destination string. The number of characters moved is
put in the POS field of the control data file. The number in the POS field
is continuously updated and the Done bit (DN) is not set until all of the
characters are read.
ARL - ASCII Read Line
Instruction Type: output
Use the ARL instruction to read characters from the buffer, up to and
including the Termination characters, and store them in a string. The
Termination characters are specified via the Channel Configuration screen.
Entering Parameters
Enter the following parameters when programming this instruction:
•
Channel
is the number of the RS-232 port, Channel 0.
•
Destination
is the string element where you want the string stored.
•
Control
is the control data file. See page 365.
(1) The Control data file is the only valid file type for the Control Element.
TIP
For information on the timing of this instruction, see the timing diagram on
page 389.
EN
DN
ER
ARL
ASCII Read Line
Channel
0
Dest
ST10:5
Control
R6:4
String Length
15<
Characters Read
0<
Error
0<
ARL
Execution Time for the ARL Instruction
Controller
When Instruction Is:
True
False
MicroLogix 1400
33.9910 µs
8.5690 µs
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