Standard Items
Protocol Items
Common Extended Items
See Common Modbus OPC Items. In addition to the common items, the Modbus SCADAPack protocol also has the following Extended items:
Modbus SCADAPack Extended Items - Common
| Item | Data Type | Description |
|---|---|---|
DateTime | Date | Date and time in the RTU. |
LastAlarmRecord/n | Date | Date and time of the last alarm record retrieved from the RTU. Specify the run number 1 to 10 for ‘n’. |
LastAuditRecord/n | Date | Date and time of the last audit record retrieved from the RTU. Specify the run number 1 to 10 for ‘n’. |
LastDailyRecord/n | Date | Date and time of the last daily record retrieved from the RTU. Specify the run number 1 to 10 for ‘n’. |
LastEventRecord/n | Date | Date and time of the last event record retrieved from the RTU. Specify the run number 1 to 10 for ‘n’. |
LastEventRecord/n | Date | Date and time of the last event record retrieved from the RTU. Specify the run number 1 to 10 for ‘n’. |
LastHourlyRecord/n | Date | Date and time of the last hourly record retrieved from the RTU. Specify the run number 1 to 10 for ‘n’. |
MoveDaily/1 | I2 | Moves the daily retrieval record position back in time. Write the number of days to move back. This item can be used to re-collect daily records. Specify the run number 1 to 10 for ‘n’. |
MoveHourly/1 | I2 | Moves the hourly retrieval record position back in time. Write the number of hours to move back. This item can be used to re-collect hourly records. Specify the run number 1 to 10 for ‘n’. |
ResetAlarm/1 | BOOL | Resets the alarm retrieval record position. Write a ‘True’ to this item to remove record position information. This will cause all alarm records to be retrieved again. Specify the run number 1 to 10 for ‘n’. |
ResetAudit/1 | BOOL | Resets the audit retrieval record position. Write a ‘True’ to this item to remove record position information. This will cause all audit records to be retrieved again. Specify the run number 1 to 10 for ‘n’. |
| ResetBatch/1 | BOOL | Resets the batch retrieval record position. Write a ‘True’ to this item to remove record position information. This will cause all batch records to be retrieved again. Specify the run number 1 to 10 for ‘n’. |
ResetDaily/1 | BOOL | Resets the daily retrieval record position. Write a ‘True’ to this item to remove record position information. This will cause all daily records to be retrieved again. Specify the run number 1 to 10 for ‘n’. |
ResetEvent/1 | BOOL | Resets the event retrieval record position. Write a ‘True’ to this item to remove record position information. This will cause all event records to be retrieved again. Specify the run number 1 to 10 for ‘n’. |
ResetHourly/1 | BOOL | Resets the hourly retrieval record position. Write a ‘True’ to this item to remove record position information. This will cause all hourly records to be retrieved again. Specify the run number 1 to 10 for ‘n’. |
RetrieveHistory | I2 | Retrieve History |
ShowAGA8 | I2 | Write the run number (1 to 10) to this item to make the AGA8 configuration data for the specified run available in Modbus registers 49780 – 49822. |
ShowNX19 | I2 | Write the run number (1 to 10) to this item to make the NX-19 configuration data for the specified run available in Modbus registers 49840 – 49848. |
TimeSync | I2 | Synchronize the real time clock in the RTU with the host computer.
|
Extended Items - EFM Configuration
The Extended Items for EFM Configuration are used to read and write the current EFM configuration values. There are separate items for reading and writing the values and all items must include the one based meter run number designator on the end.
Items to read values are in the format of "Config.{section}.{data}/n", where section is the particular EFM configuration section described below and '/n' indicates the meter run number.
Items to store write values are in the format of "Config.Write.{section}.{data}/n", where section is the particular EFM configuration section described below and '/n' indicates the meter run number.
Example: Config.AGA8.Methane/2 - read the AGA8 methane value for run 2.
Items from all EFM sections can be browsed and added by a client, even if they are not valid for the current RTU configuration. Example, items for AGA3-1985 are available but will only return an error when polled if the RTU is configured to use AGA3-1992.
For RTUs configured to use AGA3-2013, the extended items for section AGA3-1992 are used to both read and write values.
Writing New EFM Configuration Values
Writing new EFM Configuration values is a multi-step process. This is because the Scadapack protocol requires writing all data components of a section at the same time, and not individually. This process applies to all EFM sections and should be done on a per-section and a per-meter run basis.
- Write new values, using the "Config.Write.{section}.{data}/n" items, for each data point you need to change in a section. These new values are stored internally by the driver. You do not need to write a new value to any item in a section that you do not wish to change.
- Write TRUE to the item "Config.Write.{section}.ExecuteWrite/n", where '/n' indicates the meter run number. This will download all the values at once for that section. The result of the download can be monitored by the item "Config.Write.{section}.Result/n".
- To cancel the write process before the ExecuteWrite item is set, write TRUE to the item "Config.Write.{section}.Clear/n", where '/n' indicates the meter run number. This will delete the internally stored values.
Example: Write new values for AGA8 Methane and Ethane for meter run 1.
- Write new value to item Config.Write.AGA8.Methane/1
- Write new value to item Config.Write.AGA8.Ethane/1
- Write value TRUE to item Config.Write.AGA8.ExecuteWrite/1 to download new values
All Config.Write Sections
| Data Item | Details |
|---|---|
| ExecuteWrite | Initiates download of new write values for the EFM configuration section |
| Clear | Cancels the pending write values |
| Result | Result value of initiating the ExecuteWrite item |
Example: Config.Write.AGA8.ExecuteWrite/1
Sections AGA31985 and AGA31992
| Data Item | Details |
|---|---|
| DifferentialPressureDeadBand | float |
| IsentropicExponent | float |
OrificeDiameter | float |
| OrificeMaterial | AGA-3 (1985, 1992) 0 = type 304 & 316 stainless steel, 1 = Monel, 2 = carbon steel AGA-3 (2013) 0 = type 304/316 stainless steel, 2 = carbon steel, 3 = type 304 stainless steel 4 = type 316 stainless steel 5 = Monel 400 |
| OrificeReferenceTemperature | float |
| PipeDiameter | float |
| PipeMaterial | AGA-3 (1985, 1992) 0 = type 304 & 316 stainless steel, 1 = Monel, 2 = carbon steel AGA-3 (2013) 0 = type 304/316 stainless steel, 2 = carbon steel, 3 = type 304 stainless steel 4 = type 316 stainless steel 5 = Monel 400 |
| PipeReferenceTemperature | float |
| StaticPressureDeadBand | float |
| TemperatureDeadBand | float |
| Viscosity | float |
Examples: Config.AGA31985.OrificeDiameter/2, Config.Write.AGA1992.PipeMaterial/4
Section AGA8
The gas ratios are fractional floating point numbers. The sum of the values must be 1.00.
| Data Item |
|---|
| Argon |
| CarbonDioxide |
| CarbonMonoxide |
| CompositionLoggingControl |
| Ethane |
| HeatingValue |
| Helium |
| Hydrogen |
| HydrogenSulfide |
| iButane |
| iPentane |
| Methane |
| nButane |
| nDecane |
| nHeptane |
| nHexaneOrHexanesPlus |
| Nitrogen |
| Nonane |
| nOctane |
| nPentane |
| Oxygen |
| Propane |
| RealRelativeGasDensity |
| Water |
Example: Config.AGA8.Methane/1, Config.Write.AGA8.Oxygen/2
Section Contract
| Data Item | Details |
|---|---|
| BasePressure | float |
| BaseTemperature | float |
| Hour | 0 - 23 |
| Input | For Flow Computer 6.70 and newer Input average weighting 0 = flow-dependent time-weighted linear average 2 = flow-weighted linear average For Flow Computer 5.28 and earlier Input error action 0 = do not accumulate flow when inputs in error 1 = accumulate flow when inputs in error |
| Units | uint |
| WetGasFactor | Wet gas meter factor. Version 6.10 or greater. Default value is 1.0. The value 0.0 indicates that the parameter is not supported and that 1.0 should be substituted for it. For version 6.21 or greater, this parameter can be changed while flow calculations are running and without starting a new contract day. |
Example: Config.Contract.Hour/1
Section HPAGA8
| Data Item | Details |
|---|---|
| Components | 0 = Use individual gas components (default) 1 = Use combined value for hexane and higher components |
| nDecane | float |
| nHeptane | float |
| nHexane | float |
| nNonane | float |
| nOctane | float |
Example: Config.HPAGA8.Components/1
Section MeterExecution
This section's format is slightly different so the entire items are given in the table, where '/n' is the run number.
| Item | Details |
|---|---|
| Config.MeterExecutionState/n | 1 = stop 2 = run |
| Config.Write.MeterExecutionState.Clear/n | |
| Config.Write.MeterExecutionState.ExecuteWrite/n | |
| Config.Write.MeterExecutionState.Result/n | |
| Config.Write.MeterExecutionState.State/n | 1 = stop 2 = run |
Section NX19
| Data Item | Details |
|---|---|
| CarbonDioxide | float |
| CompositionLogging | Composition logging control 0 = log composition changes 1 = do not log composition changes |
| HeatingValue | float |
| Nitrogen | float |
| SpecificGravity | float |
Example: Config.Write.NX19.Nitrogen/2
Section VCONE
| Data Item | Details |
|---|---|
| AdiabaticFactor | 0 = Legacy 1 = V-Cone 2 = Wafer Cone |
| ConeDiam | float |
| ConeDiamRefTemp | float |
| IsentropicExponent | float |
| MassFlowRate | float |
| NumberPoints | 1 - 10 |
| PipeMat | 2 = carbon steel, 3 = stainless 304 4 = stainless 316 |
| PT1C | Point 1 Coefficient - repeated for 10 points |
| PT1R | Point 1 Reynold’s number - repeated for 10 points |
| PT2C | |
| PT2R | |
| PT3C | |
| PT3R | |
| PT4C | |
| PT4R | |
| PT5C | |
| PT5R | |
| PT6C | |
| PT6R | |
| PT7C | |
| PT7R | |
| PT8C | |
| PT8R | |
| PT9C | |
| PT9R | |
| PT10C | |
| PT10R | |
| VConeMat | 2 = carbon steel 3 = stainless 304 4 = stainless 316 |
| Viscosity | float |
| WetGasFactor | 0 = Legacy Method 1 = V-Cone or Wafer Cone |
Example: Config.VCONE.Viscosity/1
Related Topics:
Common Modbus OPC Item Conversion