Messages can come in many different formats, lengths and syntaxes.
CRT or could be present on a printer that is dedicated to event logging. Alarm filtering can also be performed, which can dramatically reduce the amount of nuisance alarms. Once a rule has been found that matches the general format of a particular line or set of lines, the message is considered to be framed. This is ideal for those devices that do not have the ability to report on change of state, but do have a status report command. Each logical channel can follow its own set of rules.