ARL (ASCII read line)

The ARL instruction reads a line of ASCII characters from the buffer, up to and including the termination characters, and stores them in a string.

Languages supported: Function block diagram, ladder diagram, structured text.

This instruction applies to the L20E, L50E, and L70E controllers.

ARL parameters
Parameter	Parameter Type	Data Type	Description
IN	Input	BOOL	Rung input state. TRUE: When Rising Edge is detected, start the instruction block with the precondition that the last operation is complete. FALSE: The instruction block is idle.
ARLInput	Input	ARDARL data type	Read a line of ASCII characters from the buffer. The maximum is 82. Use the ARDARL data type to define the Channel, Length, and Cancel parameters for the ARDLInput.
Q	Output	BOOL	Indicates when the read line from the input buffer is ongoing or complete. Outputs of this instruction are updated asynchronously from the program scan. Output Q cannot be used to re-trigger the instruction because IN is edge triggered. TRUE: The function block is complete. FALSE: The function block is not complete.
Destination	Output	ASCIILOCADDR	The string element where the characters are stored.
NumChar	Output	UINT	The number of characters in the line, including the termination character.
Error	Output	BOOL	Indicates the existence of an error condition. TRUE: An error is detected. FALSE: No error.
ErrorID	Output	UINT	A unique numeric that identifies the error. The errors for this instruction are defined in ABL error codes.

ARL error codes
Error code	Error description
03	Transmission cannot be completed because the Clear-to-Send signal was lost.
06	Illegal parameter was detected.
07	Cannot complete ASCII send or receive because channel configuration has been shut down using the channel configuration dialog.
08	Cannot complete ASCII Write due to an ASCII transmission already in progress.
09	ASCII communication requested is not supported by current channel configuration.
10	The Cancel was set, stopping instruction execution. No action required.
11	The requested length for the string is either invalid, a negative number, greater than 82, or 0. Applies to ARD and ARL function blocks.
13	The requested (.LEN) in the control block is a negative number or a value greater than the string size stored with the source string. Applies to AWA and AWT function blocks.
14	The ACL function block was canceled.
16	Serial port is not supporting RTS or CTS control lines.

ARL examples

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