Ascii Test For Buffer Line (Abl); Relay Ladder; Structured Text; Serial_Port_Control Structure - Allen-Bradley Logix5000 Reference Manual

Chapter 17 ASCII Serial Port Instructions (ABL, ACB, ACL, AHL, ARD, ARL, AWA, AWT)
ASCII Test For Buffer Line
(ABL)
ABL
ASCII Test For Buffer Line
Channel
SerialPort Control
Character Count
ABL(Channel
SerialPortControl);
Mnemonic Data Type
.EN BOOL
.EU BOOL
.DN BOOL
.RN BOOL
.EM BOOL
.ER BOOL
.FD BOOL
.POS DINT
.ERROR DINT
578
The ABL instruction counts the characters in the buffer up to and including the
first termination character.
Operands:

Relay Ladder

Operand
EN
Channel
? DN
? ER
?
Serial Port
Control
Character
Count

Structured Text

The operands are the same as those for the relay ladder ABL instruction. You
access the Character Count value via the .POS member of the

SERIAL_PORT_CONTROL structure.

SERIAL_PORT_CONTROL Structure
Description
The enable bit indicates that the instruction is enabled.
The queue bit indicates that the instruction entered the ASCII queue.
The done bit indicates when the instruction is done, but it is asynchronous to the logic scan.
The run bit indicates that the instruction is executing.
The empty bit indicates that the instruction is done, but it is synchronous to the logic scan.
The error bit indicates when the instruction fails (errors).
The found bit indicates that the instruction found the termination character or characters.
The position determines the number of characters in the buffer, up to and including the first set of
termination characters. The instruction only returns this number after it finds the termination character
or characters.
The error contains a hexadecimal value that identifies the cause of an error.
Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Type Format
DINT Immediate
Tag
SERIAL_PORT_ Tag
CONTROL
DINT Immediate
Description
0
Tag that controls the operation
0
During execution, displays the number of
characters in the buffer, including the first set
of termination characters.