8315 L&J Tankway Software Description | TankGate Interface |
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4.3Database Organization
Points are the individual instances of software blocks. Examples include Whessoe Varec 1900 (WV1900) and SCALER points. In both cases the user configures the Config parameters and is provided real time data through the Dynamic parameters.
4.3.1Point Format
Data parameters in the TankGate are addressed using a “Type.Number.Parameter” format. For example, “WV1900.02.Level” refers to WV1900 Tank Gauge #2’s IEEE floating point level. This format and corresponding fields are described below.
The TYPE field represents the Point Type. There are many different point Types in the TankGate, referred to generically as TankGate Software Blocks. Some of the point types include the COM (Communications), SYS (System), WV1900 (WV1900 Tank Gauge) point types. Each Type performs a different function.
The NUMBER field represents the instance of the point type. For example, the AI point may have up to 32 instances, which are addressed using the NUMBER field. Each instance shares the same data structure definition, yet each point has unique data values. In the case of the AI software block, each point manages a single input channel.
The PARAMETER field represents the items in the data structure of the point type. Examples of parameters include Value, Status, PntRef and RawValue. This field is explained in greater detail in the following section.
4.3.2Parameter Description
Each parameter is defined by its Parameter Class and Data Type. The following subsections describe Parameter Classes, Parameter Data Formats and Common Parameters.
4.3.2.1Parameter Classes
Each parameter, such as Value or Channel, is classified as one of the following classes:
Parameter | Description |
Class |
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Config | Configuration parameters such as channel numbers, tags, descriptions, |
| ranges, operating modes, point references, constants for formulas and |
| timing information. |
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Dynamic | |
| measured during point execution scans, which occur every 250 msec. |
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Command | Output command data |
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Constant | Weights & Measures parameter |
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Scratch | Temporary data that is typically hidden from the user |
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System | System data (should not be changed by the user) |
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24 | Installation and Operations Manual |