National Instruments BridgeVIEW

Appendix A HMI Function Reference

value is the latest value of the discrete tag read from the Real-Time

Database.

value timestamp returns the timestamp for when the tag value was last

updated.

error indicates that an error occurred when executing the Read Tag

(discrete) VI, or that the value output returned by Read Tag(discrete) is not

valid. See value status for the specific error condition.

shutdown indicates that the BridgeVIEW Engine is shutting down. In this

case, Read Tag (discrete) 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 Read Tag (discrete).

changed? is TRUE when Read Tag (discrete) returns a new value from the

Real-Time Database. If changed? is FALSE, Read Tag (discrete) probably

timed out before the tag value was updated.