Rate
This is a function of the LagCorrection class.
Description
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.
Parameters
| 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) |
Returns
The number of seconds of lag between the origin time and when amount has passed/flowed/been seen.
Notes and Behaviour
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.
Example
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))