====LAG====

===Parameters===

^Order^Name^Type^Desc^
|1|a|[[map|map]]|A map containing parameters for [[fGETHISTORY]] |
|2|b|[[const]]|A number of seconds to 'bump' the requested range|

===Returns===

Places an updated version of the [[map|map]] on the stack

===Description===

This function is used to adjust the times in the parameters to a [[fGETHISTORY]] command by the given number of seconds.

Positive amounts will move the start/end/range of the query **back**, while negative amounts will move the results **forward** in time.

This function is normally used when you are using user-selected time-frames and want to adjust for a //time lag// between assets.

This function is often used along-side [[fUNLAG]], which moves the time-stamps in the history of a set of [[point list|points]].

===Example===

We want to query 15 minutes of data. But we don't want to include the **last two minutes**. We can do this by pushing our start and end times back by 120 seconds.

'Wind Turbine #1' [[fASSET]] 'Power' [[fPROPERTY]] {"range": "15 minutes"} 120 LAG [[fGETHISTORY]]

If you're trying to synchronise multiple channels of data from different sources, you might want to use [[fUNLAG]] to adjust the timestamps returned by GETHISTORY.

===See Also===

[[fUNLAG]]