Event Message Texts is a simple triple of character strings that a device can use to supply human-readable messages for each of the three possible event state transitions. The three fields correspond to the messages that should be sent when the object transitions to-Offnormal, to-Fault, and to-Normal.

These texts are optional in most object types. When present, they are usually copied into the Event Message Text parameter of ConfirmedEventNotification and UnconfirmedEventNotification messages. This gives receiving systems (workstations, pagers, logging systems, etc.) a pre-formatted description of what the alarm means without requiring them to perform a separate Read Property to obtain the description.

Because the strings travel with the notification itself, they are especially useful in environments where the notification recipient does not have full read access to the alarming device or where low-bandwidth transports make additional round-trips expensive.