Use Data Set Marking I/O Servers
- Updated2025-11-07
- 4 minute(s) read
You can create data set I/O servers with the LabVIEW Datalogging and Supervisory Control (DSC) Module to read and write groups of shared variables logged together as a set during a specific period of time, or data sets.
Right-click My Computer or a LabVIEW project library in the
Project Explorer window and select New»I/O
Server from the shortcut menu to display the Create New I/O
Server dialog box. You then can select Data Set
Marking and click the Continue button to display
the Configure Data Set Marking I/O Server dialog box. Use the
Configure Data Set Marking I/O Server dialog box to configure
the data set marking I/O server.
Note You can configure a data set marking I/O server only if the project
library from which you create the I/O server contains a shared variable.
You can use data set marking I/O servers to log statistical data, such as the batch process that is running, the current ID of the batch process, and so on.
The following table lists the data items that LabVIEW creates when you create and configure a data set marking I/O server. Use the View I/O Items dialog box to view the data items. You also can monitor these data items by using the Distributed System Manager. To launch the System Manager from LabVIEW, select Tools»Distributed System Manager.
| Data Item | Data Type | Read | Write | Description |
|---|---|---|---|---|
| active | Boolean | Yes | No | Returns whether a start or end condition for a data set run is met. The value is TRUE after the start condition is met and until the end condition is met. |
| alarm_area | String | Yes | Yes | Specifies the alarm area of this data set instance. The server generates an alarm if the configuration is bad. |
| alarm_priority | Double | Yes | Yes | Specifies the alarm priority of this data set instance. The server generates an alarm with this priority if the configuration is bad. |
| configure_start_end_condition | Boolean | Yes | Yes | Specifies whether the start and end conditions are configured. If the value is TRUE, the data set waits for new configuration to be written before starting. |
| current_start_run_time | Double | Yes | No | Displays the current data set run start time if a run is active. The units are in UTC seconds. |
| currentid | String | Yes | No | Reports the ID tag value for the current data set run, while the data set run is active. |
| dataset_server_state | String | Yes | No | Displays the current state of the data set server. For example, if active=TRUE, dataset_server_state=Wait for stop. If active=FALSE, dataset_server_state=Wait for start. Possible states are Verify Configuration, Wait for start, Wait for stop, Post End of Run, and Wait for config transition. |
| desc | String | Yes | Yes | Specifies the description of the data set. If you write to this data item, the description updates at the start of the next data set run. |
| end_condition | Double | Yes | Yes | Specifies the type of end condition to use for the next data set run. Depending on the end condition, you may need to update other items. |
| end_limit_numeric | Double | Yes | Yes | If end_condition uses numeric comparisons, this data item compares with the value of end_tag to determine whether the end condition has been met. |
| end_tag | String | Yes | Yes | Specifies the tag to use for testing the end condition. The data type must be compatible with the data type of the end condition. |
| end_value_string | String | Yes | Yes | If end_condition is set to String SV=Value, this data item compares with the value of end_tag to determine whether the end condition has been met. The comparison is case sensitive. |
| equip | String | Yes | Yes | Lists the equipment for the current data run. You can write a tab-delimited spreadsheet-style string, rows by EOL (end-of-line) characters, or a flattened 2-dimensional array of LabVIEW strings to this data item. Changes take effect when the next run starts. |
| idtag | String | Yes | Yes | Specifies this tag as the ID tag when the next data set run starts. |
| internal_id | Binary string | Yes | No | Returns an internally generated, 8-byte binary identifier that is unique for each data set. This data item identifies each data set run. |
| name | String | Yes | No | Specifies the name of the data set configuration. |
| previous_run_duration | Double | Yes | No | Displays the last run duration. The units are in UTC seconds. |
| previous_run_end_time | Double | Yes | No | Displays the last run end time. The units are in UTC seconds. |
| previous_run_id | String | Yes | No | Reports the ID tag value for the previous data set run, while the data set run is active. |
| start_condition | Double | Yes | Yes | Specifies the type of start condition to use at the beginning of the next data set run. Depending on the start condition, you may need to update other items. |
| start_limit_numeric | Double | Yes | Yes | If start_condition uses numeric comparisons, this data item compares with the value of start_tag to determine whether the start condition has been met. |
| start_tag | String | Yes | Yes | Specifies the name of the tag for testing the start condition. The data type must be compatible with the data type of the start condition. |
| start_value_string | String | Yes | Yes | If the start_condition is set as String SV=Value, this data item compares with the value of start_tag to determine whether the start condition has been met. The comparison is case sensitive. |
| tags | String | Yes | Yes | Specifies the list of tags in the data set, delimited by EOL characters. If specified, the set of tags in a data set will be used when the next data set run starts. You can write either an EOL-delimited text string or a flattened LabVIEW array of strings to this tag. |