National Instruments BridgeVIEW Manual Do Utilizador

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Appendix A
HMI Function Reference
© National Instruments Corporation
A-55
value timestamp returns the timestamp for when the tag value was 
updated. 
error indicates that an error occurred when executing the Read Tag VI, or 
that the value output returned by Read Tag is not valid. See value status 
for the specific error condition.
shutdown indicates that the BridgeVIEW Engine is shutting down. In this 
case, the Read Tag VI no longer waits for tags to be updated and returns 
immediately with both timeout and shutdown TRUE. You can use 
shutdown to exit any loop that uses the Read Tag VI. 
changed? is TRUE when the Read Tag VI returns a new value from the 
Real-Time Database. If changed? is FALSE, the Read Tag VI probably 
timed out before the tag value was updated.