Rockwell Automation FactoryTalk Historian SE 4.0 Live Data Interface User Guide - Manual (Page 31)

Point Configuration Chapter 5
Rockwell Automation Publication HSELD-UM024A-EN-E–September 2013 31
• Scan Class 4 has a scan period of 5 seconds, with an offset of 1
second.
Polled tags are read once every scan period. To set up a polled tag, set
Location1 to match the /ID parameter, Location3=0, and
Location4=scanclass#.
For example:
Tag InstrumentTag Loc1 Loc2 Loc3 Loc4 Loc5
FiveSec.PV ItemID1 1 0 0 1 0
OneMin.PV ItemID2 1 0 0 2 0
NinetyMin.PV ItemID3 1 0 0 3 0
For Advise tags, the interface asks the FTLD server to send data
when it changes, and how often it should read the device to see if
there is a new value.
For example:
Tag InstrumentTag Loc1 Loc2 Loc3 Loc4 Loc5
AdvFiveSecs.PV ItemID1 1 0 1 1 0
AdvOneMin.PV ItemID2 1 0 1 2 0
AdvNinetyMins.PV ItemID3 1 0 1 3 0
Event tags are read when the triggering event occurs. An event
happens when the FactoryTalk Historian snapshot receives a value
for the trigger tag. It may have the same time stamp and quality and
value as the last event so the snapshot value for that trigger may seem
the same, but the act of receiving a value for the trigger tag causes the
interface to receive a notification that the trigger has been updated.
To configure triggered input tags, specify the name of the trigger tag
in the ExDesc field using the following format:
Polled Tags
Advise Tags
Event Tags