National Instruments BridgeVIEW 用户手册
Appendix A
HMI Function Reference
A-32
© National Instruments Corporation
historical trend is the tag trend data read from the historical database,
starting at the date and time specified by start timestamp, and stopping at
the date and time specified by stop timestamp or up to max points per
trend, whichever is smaller. If these start timestamp and stop timestamp
values are left unwired, all the logged data up to max points per trend for
the tag is returned.
starting at the date and time specified by start timestamp, and stopping at
the date and time specified by stop timestamp or up to max points per
trend, whichever is smaller. If these start timestamp and stop timestamp
values are left unwired, all the logged data up to max points per trend for
the tag is returned.
timestamp is the date and time for value.
value is the value of the tag at the timestamp.
error out is a cluster that describes the error status after this VI executes.
For more information about this indicator, see the section
For more information about this indicator, see the section
in this appendix.