National Instruments BridgeVIEW - Manual (Page 330)

Appendix A HMI Function Reference
BridgeVIEW User Manual A-10 © National Instruments Corporation
shutdown indicates that the BridgeVIEW Engine is shutting down. In this
case, the Read Alarm Summary VI returns immediately with shutdown
TRUE. You can use shutdown to exit any While Loop that calls Read
Alarm Summary VI.
changed? is TRUE if a new alarm was read. If changed? is FALSE, the
Read Alarm Summary VI probably timed out before the Alarm Summary
Display was updated.