This read-write INTEGER specifies the action taken when the falling threshold is crossed, with values tcaTrap(1) to send an SNMP trap, tcaLog(2) to record a local log entry, or tcaIgnore(3) to take no action. An admin configures this to control notification behavior for downward threshold crossings, mirroring the rising-event control but for the falling case. As an illustrative example, an admin might set this to tcaLog(2) so a falling signal level is recorded locally without generating a trap flood.