Signature analyzer or analyser

- a summary or tutorial about the signature analyzer or signature analyser, used for fault finding digital or logic electronics circuits

The signature analyzer or signature analyser was an item of test equipment that was used for fault finding electronics circuits.

In view of the significant increase in complexity of logic circuits the signature analyzer is little used these days.

Also few signature analyzers are available these days as most are now obsolete items in the test equipment manufacturers' catalogues.

In its day, the signature analyser provided a very easy to use and convenient method for fault finding electronics logic circuits.

Signature analyzer basics

A signature analyzer is normally used for checking data on given nodes within a logic system such as a microprocessor board. A known operational scenario is set up, e.g. a test mode, and the data on various nodes may be monitored. The signature analyzer converts the serial data into a hexadecimal equivalent of the data pattern - this is the signature. Typically this signature is four digits long, although different signature analyzers may have different lengths.

If the signature captured by the signature analyzer aligns with that of the same node on a known good board, then this indicates this area is operating correctly.

By probing different areas of a board with the signature analyzer, and comparing the results with expected values, often detailed in a repair and service manual, it is possible to locate the problem area.

By Ian Poole