This is a function of the LagCorrection class.
This function is used to calculate a lagged time based on a rate.
Use this if the source of your lag is counting the speed or rate that your target is moving, instead of being measured with a counter. Note that in many industrial applications, field-based counters or totalisers are more accurate that performing calculations than rates are.
For example, you might have a conveyor system that has a speed measurement. If Sensor X is 50m away from Sensor Y, you can calculate the time lag between Y and X by going backwards and finding out how long it took for 50m of conveyor to pass.
| Parameter | Type | Meaning |
|---|---|---|
| server | ARDI API Server | The ARDI server to query |
| query | string | The AQL Query to send |
| amount | float | The amount to lag the time by |
| origin | datetime | The ending/reference time (default=now) |
| seconds | int | The maximum number of seconds to search (default=1 day) |
| expected | int | The average amount of time in normal operation (default=10 minutes) |
The number of seconds of lag between the origin time and when amount has passed/flowed/been seen.
The expected time should be the maximum amount of lag you'd expect to have during normal operation (ie. if your machines didn't stop in the mean-time).
The seconds time should be the maximum amount of lag you're willing to search for.
srv = ardiapi.Server('demo.optrix.com.au/s/pl') query = "'Paint Line' ASSET 'Distance' PROPERTY VALUES" lc = samplestream.LagCorrection() diff = lc.Amount(srv,query,25) print("Roller 2 Lag Correction - " + str(dt))