Points / Point Types List
Introduction
Clicking on the Points / Point Types List menu displays the Point Types List page.
Defined Point Types allow users to organize sensor parameters, including data units, data calibration and data checking parameters, around specific types of sensors. Point types are used to define raw data checking parameters specifically for counters, encoders, and digital status sensors.
Data checking parameters and calibrations can also be specific to individual points if required, because most point types, for example those that measure stream depth, are typically individually calibrated at each station so that measured stream depths are converted into calibrated water surface elevations. See the Overview section for a complete discussion of points and point calibrations.
Point Types List (see full-size image)
NovaStar provides predefined point types in the Point Type List. The point types that will be needed for most systems are included on the list, but users should confirm that the point type parameters are set as desired before using predefined point types. Click the Add button at the upper right-hand corner of the Point Type List table to create a new point type. Or, select a point type in the Point Type List and click the Copy button to use that exiting point type as a template for creating a new point type.
Navigation, Adding, Deleting, Modifying, and Copying Point Types
See Application Functionality for more information about basic component functionality.
The Point Type List page conforms to a layout similar to many data types which includes a list of data items. See List Featuresyy for more information detailing page navigation; adding, copying and deleting point types; and modifying existing point types.
Adding a new point type
Note that creating a new point type requires entering the name and point class.
Identification
The following properties are used to identify the point type.
Point Type Identification (see full-size image)
| Data Label | Description |
|---|---|
| Name | Unique identifier for the point type being created. Max: 100 characters. This name will appear in reports and point pick lists. Enter a name that will be recognized when are setting up points such as water level PT, water level encoder, precipitation 1-mm, wind speed, battery, etc. If different calibrations are available for tipping-bucket rain gages of different volumes, for example, there may be more than one point type for that sensor. However, calibrations can also be associated with specific points for sensors that require individual calibration at each station. |
| Description | Additional information describing attributes of the point type. Because many point types are similar, it may be helpful to differentiate between them by describing physical attributes or vendor make and model number. Max: 1000 characters. |
| Short name | Short name for the point type. This is used in reports where a shortened text field may be required. Max: 100 characters. |
| SHEF code | SHEF parameter code as described in the National Weather Service Standard Hydrologic Exchange Format documents. A reference to all the parameter codes can be found at: https://www.weather.gov/media/mdl/SHEF_CodeManual_5July2012.pdf. A list of the most commonly used SHEF codes and the associated NovaStar data type can be viewed in the Reference / Data types and SHEF codes section of this documentation. Using the appropriate SHEF code is critical. NovaStar's Data Web Services, which supplies data for most TriLynx applications such as Operator and Data Explorer, uses this code to filter and return requested data. Max: 7 characters. |
| Point Class | Select point class assigned to point type from the pick list. The point class determines how NovaStar checks and processes data based on the expected behavior of the measurement sensor. See the Point Class section for additional point class information. See the Point Class List table below for a summary point type list. |
| Computation | Select the type of point class computation (alertwind only). none: no computation wind speed: compute wind speed from wind run wind direction: extract wind direction from alertwind point class data. |
| Control | Remote control type. Stations that have control points will have this parameters changed from "none" to "set value" to enable remote control through the web page. |
Point Class List
| Class | Description | Example |
|---|---|---|
| Analog | Values range up and down | Pressure transducer |
| Alertwind | Combined wind run and direction | ALERT wind |
| Counter | Count up only with roll-over | Rain gage |
| Encoder | Count up and down with roll-over | Shaft encoder |
| Flag | Values relate to messages | System messages |
| Flow | Discharge or flow measurement | Model output |
| Status | Digital status | Float switch |
| Wind | Wind run counter | Anemometer |
| Total | Totaled data | Model input |
User Groups
The User groups table shows the user groups currently assigned to the point type. For more information, see the User Groups documentation.
User Groups Assigned (see full-size image)
Data Units
Data unit fields are not shown for point class Flag or Status.
Point Types Data Units (see full-size image)
| Data Label | Description |
|---|---|
| Units | Sensor value data units (plural). Max: 100 characters. |
| Unit | Sensor value data unit (singular). Max: 100 characters. |
| Abbreviation | Sensor value abbreviated data units. Max: 100 characters. |
| Raw digits | Number of digits to display to the right of the decimal point when raw data is displayed. |
| Scaled digits | Number of digits to display to the right of the decimal point when scaled data is displayed. |
| Cycle size | Raw data reading where count is reset to 0. This field is only shown for the point classes listed in the table below Point Type - Cycle Size Examples. |
Point Type - Cycle Size Examples
| Class | Sensor Example | Cycle Size |
|---|---|---|
| Counter | 5096 rain gage | 2048 |
| Counter | 0850 rain gage | 65536 |
| Encoder | 5096 shaft encoder | 2048 |
| Wind | 5096 wind counter | 2048 |
| ALERTwind | 5096 ALERT wind sensor | 32 |
Data Calibrations
Data reported by station sensors is raw data. This data needs to be converted into engineering units using appropriate calibration values. The scaled data is displayed in reports and used in data analysis. Raw data is calibrated using the calibration formula:
Cal data = Raw data * Multiplier + Adder + Base value
Point Types Data Calibration (see full-size image)
| Data Label | Description |
|---|---|
| Multiplier | Multiplier term (slope) in the calibration equation. |
| Adder | Add term (offset) in the calibration equation. |
| Base Value | Base value term (elevation) in the calibration equation. |
| Display type | Select the type of data display. Numeric displays floating point numeric values. String displays the name of the flag number or status line state. Heading displays a compass heading (N, NNE, NE, ...) |
NOTE: Data calibrations are only assigned to newly added points. Changing the data calibration for a point type will not change data calibrations for point already defined.
Data Checking
The Data Checking parameters determine how NovaStar validates data reports when they are filed in the database. Reports received with bad data values or values out of limits are flagged as questionable and are not used in data analysis or displays. Default data checking parameters can be copied from the assigned point type but they can also be individually set for each point.
Point Types Data Checking (see full-size image)
| Data Label | Description |
|---|---|
| Change | Allowed change in a data report scaled value from previous reports to detect questionable data values. The difference between each scaled data value and the scaled values received before are compared to the allowed Change to detect questionable data values. If the reported value has changed by more than the allowed amount, the data point is not validated and is marked as questionable. Data checking does not stop after one report validates the new value. A data report is validated if it does not change by more than the Change amount from the last report, twice the amount from two reports prior, or three times the amount from three reports prior. The checking continues until one of the 3 reports validates the new report or 3 reports that were already validated do not validate the report. The data checking interval for previous reports is limited to the larger of the no report interval, change interval, alarm set or reset intervals. Reports already stored in the database that were marked as questionable can be changed to valid by a new report. In this last case the earlier report that is validated is marked with a break flag to indicate the start of a new data series. A 0 value disables data change validation. |
| Repeat | Number of repeated identical reports required for digital status report verification. |
| No Report Interval | Minimum reporting time interval. Remote sensor data does not always report in at regular time intervals but it should report at a minimum time interval. For example, rain gages should be configured to report every bucket tip, but also to report within a minimum time period during dry weather to provide assurance that the sensing and transmission system is continually working. In doing so, problems are detect before the station fails to provide data at a critical time. When remote data is not received at the minimum time interval, validated data is marked with a break flag to indicate a gap in the data record. A 0 value uses the default 1 day interval. |
| Upper limit | Scaled data values greater than this value are flagged not valid. |
| Lower limit | Scaled data values less than this value are flagged not valid. Before checking the change from one report to the next, the data checking compares the scaled data value to the upper and lower limits. Any report greater than the Upper Limit is not validated regardless of whether the change in scaled value from surrounding reports is less than the allowed amount. Any report less than the Lower limit is not validated regardless of whether the change in scaled value from surrounding reports is less than the allowed amount. Set both the Upper limit and the Lower limit to zero (or blank) to disable limit checking. |
| Change limit | Scaled data value change over time limit. |
| Change interval | Change limit time interval. The Change limit over Change interval data checking tests the scaled data value change over a time interval. This check is done after the change between reports has validated a data report scaled value. Changes over the interval that are greater then the limit will remove the report validation. This type of data checking can be used for sensors like rain gauges where the upper and lower limits do not apply well. A malfunctioning sensor will report too often and can be detected by this test. Set the Change limit to zero or blank to disable change limit checking. |
| Compress interval | Data compression time interval. When remote station data reports the same value at time intervals shorter than the minimum data recording interval, the duplicate data reports can be removed by setting a compress interval. Use 0 to disable data compression. |
Point Type Flag Names
The Flag names list the strings that will be displayed for point data values assigned to this point type. Flag names are only displayed when the point type display type is set to string.
Point Type Flag Names (see full-size image)
| Data Label | Description |
|---|---|
| Number | Point scaled data value for this flag name. |
| Name | Flag name string. |
See Sublist Functionality for more information about adding, deleting, and editing sublists.
Point Class
A point class determines how the NovaStar system processes raw data and analyzes scaled data. This includes validation, calibration, and data storage into multiple points. The point classes preloaded into NovaStar are sufficient to process all raw data type for incoming data streams. Creating a new point class is not provided in NovaStar.
Point Class Raw Data Validation
The raw data range is limited for the counter, encoder, wind classes by the point type cycle size. If the cycle size is greater than zero, then raw data values greater than or equal to the cycle size are not validated. The alertwind class is a special case where the raw data is composed of the wind direction in the lower 6 bits, and the wind run counter in the upper 5 bits. The wind run counter is extracted from the upper 5 bits before it is tested. Shifted wind run counter data values greater than or equal to the cycle size are not validated.
Point Class Counter Roll-over Detection and Recalibration
The raw data changes must be positive for counter classes. If the data change is negative, then the data is tested for a roll-over event. A roll-over event occurs when a counter is incremented past the cycle size supported by the data logger memory or data transmission format. When a roll-over event is tested, the cycle size is added to the raw data counter.
If the adjusted data value has a positive change then the data is calibrated and validated.
If the adjusted data value is validated, a new calibration record is
added to the system for the point at the time of the data report.
The new calibration base value is set to the last calibration base value + multiplier * cycle size.
If the adjusted data value is not validated, then the data report must be validated by another report received later. When the report is finally validated, the calibration base value is reset to zero if not already zero and a break flag is set in the report flags.
Point Class Encoder Roll-over Detection and Recalibration
The raw data changes can be positive or negative for encoder classes. If the change in data is not validated by the data checking change limit, then the data is tested for a roll-over event. A roll-over event occurs when a counter is decremented below zero or incremented past the cycle size supported by the data logger memory or data transmission format.
The scaled cycle size is added to the calibrated data value
and the adjusted data value is tested for validation.
If the adjusted data value is validated, then a new calibration
record is added to the system for the point at the time of the data report.
The new calibration base value is set to the last calibration base value + multiplier * cycle size.
If the adjusted data value is not validated, then the scaled cycle size is
subtracted from the calibrated data value and this adjusted data value is tested for validation.
If this adjusted data value is validated,
then a new calibration record is added to the system for the point at the time of the data report.
The new calibration base value is set to the last calibration base value - multiplier * cycle size.
If neither the positive or negative adjusted data value is validated, then the data report must be validated by another report received later. When the report is finally validated, the calibration is unchanged and a break flag is set in the report flags.
Point Class Alertwind Computation
The alertwind class has raw data that is composed of the wind direction in the lower 6 bits, and the wind run counter in the upper 5 bits. Raw data for this class must be stored in two different points. Each point will have the same remote ID but different point ID and tags. The wind direction is stored in a point data report whose point type class is alertwind and computation is wind direction. The wind speed is computed by taking the difference in the wind run counter from the previous report and dividing by the time (in hours) between reports. The resulting wind speed data value in units per hour is stored in the point data report whose point type class is alertwind and computation is wind speed.
Point Type Delete
To delete a point type from the Point Type List, select the point type, click Edit and then click Delete. The page prompts again with a popup to confirm the deletion. A point type that is assigned to a point cannot be deleted. The point must first be deleted or reassigned to a different point type.