# System Functions

LRC( ) | Longitudinal-Redundancy Check

## Format

LRC(string$[,ERR=stmtref])
Where:

string$ | Character string whose longitudinal redundancy checksum is to be calculated.
stmtref | Program line number or statement label to which to transfer control.

## Returns

One-byte string, longitudinal checksum.

#### Note:
The LRC( ) function is used primarily in conjunction with synchronous communications.

## Description

The LRC( ) function returns the longitudinal redundancy checksum of a character string. The longitudinal redundancy check of a character string is a one-byte string resulting from a logical XOR( ) comparison of all the characters in the string.

## Example

A$=hta(lrc($0102$)) ! yields Hex 03
A$=hta(lrc($0305$)) ! yields Hex 06