The Sasquatch calculates the surface velocity of the plunger on each arrival event. This is stored in a log with the latest value being available at the head of the log. As new arrivals come in, older entries are all pushed down. When the log is full, the oldest entry is pushed off the end.
Reading the top of the log after the arrival switch closes or once the New Velocity Indicator (register 1:0012) has been set will give you the latest arrival and velocity information.
Vision Device Management
If you are just getting started with the Sasquatch and don’t yet want to integrate with your controls or SCADA system, you can use the SCADA tab that is built into Vision. This tab has a pre-configured set of screens that work with Sasquatch.
Arrival Log
The arrival log in the Sasquatch contains several pieces of information per entry. Each type of information is grouped together in a array with the same type of data from each log to make retrieval simpler.
Log Count (3:0101)
This is a single 16 bit register that contains the number of valid log entries. Each arrival will cause this to increment. It is set back to 0 (zero) when reset.
The Sasquatch will store up to 120 log entries.
Arrival Time (3:0102 – 3:0107 x 120)
The arrival time is an array of 120 Dates/Times. This represents the date/time that the plunger arrived.
The date and time (registers 4:0002 – 4:0007) must first be set if you want arrivals to show up as the correct date and time.
Velocity (8:0822 x 120)
The velocity for each arrival is stored in an array of 16 bit values after the arrival times.
The units of the velocity will be set dependant on the selected units (Register 0:0005).
0 = Imperial (ft/min)
1 = Metric (m/min)
Velocity Calculation/Confidence Code (3:942 x 120)
This is an array of 16 bit values that indicates the quality of the velocity number.
- 1 – 8: Number of data points used to calculate velocity
- 20: Velocity under range
- 21: Velocity over range
- 22: Waveform sync failure
- 23: False arrival
Kinetic Energy (3:1062 x 120)
The kinetic energy of the plunger impact will be calculated and stored for each arrival provided that the plunger mass has been written (register 4:0061).
To correctly calculate the kinetic energy of the arrival, the mass must be written in same system of measurement as the velocity above.
Imperial = pounds (lbs)
Metric = kilograms (kg)