Methods of error detection

Learning objectives

Explain why errors can be introduced when data is transmitted, and describe the consequences of an error that is never detected

Apply an odd or even parity check to a byte, work out the value of the parity bit, and explain why a parity check cannot detect two errors within the same byte

Use a parity block check to identify the exact bit that has changed, by finding the row and the column whose parity has failed

Describe how a checksum and a check digit are each calculated and then compared at the receiving end, and state a typical use of each

Describe an echo check and an automatic repeat query, and explain how a positive or negative acknowledgement together with a timeout leads to a packet being sent again