584 Rockwell Automation Publication 1756-RM003N-EN-P - October 2011
Chapter 17 ASCII Serial Port Instructions (ABL, ACB, ACL, AHL, ARD, ARL, AWA, AWT)
Arithmetic Status Flags: Not affected
Fault Conditions: None
Execution:
Example: When the controller enters Run mode, clear the buffer and the ASCII queue.
Relay Ladder
Structured Text
osri_1.InputBit := S:FS;
OSRI(osri_1);
IF (osri_1.OutputBit) THEN
ACL(0,0,1);
END_IF;
Condition Relay Ladder Action Structured Text Action
Prescan The rung-condition-out is set to false. No action taken.
Rung-condition-in is false The rung-condition-out is set to false. N/A
Rung-condition-in is true The instruction executes.
The rung-condition-out is set to true.
N/A
EnableIn is set N/A EnableIn is always set.
The instruction executes.
Instruction execution The instruction clears the specified instructions and buffer(s).
Postscan The rung-condition-out is set to false. No action taken.
S:FS
ASCII Clear Buffer
Channel 0
Clear Serial Port Read 1
Clear Serial Port Write 1
ACL