Service functions - is an interface to access the OpenSCADA system through the OpenSCADA control interface from external systems. This mechanism is the basis for all exchange mechanisms within OpenSCADA, implemented through weak links and standard exchange protocol of OpenSCADA. Its main advantage is the priority processing and the possibility of using non-standard packaging data. For access to normal data you can use the standard commands of the control interface.
These requests let you to obtain detailed information about the parameters of the subsystem "Data acquisition", to acquire the values of all attributes of the parameters, and also to make the group setting. Detailed information about requests is given in Table 23.
Table 23. Attributes of the request commands of the attributes' parameters of the subsystem "Data acquisition"
| Id | Name | Value |
| Request command of information about the attributes of the parameter: <list path="/sub_DAQ/mod_{SRC}/cntr_{CNTR}/prm_{PRM}/%2fserv%2fattr"/> | ||
| <el id="iatr"/> | Information of the attributes | In separate tags the information about attribute is returned. |
id | Attribute's ID | The character identifier of the single attribute. |
nm | Attribute's name | The name of the single attribute. |
flg | Attribute's flags | Flags of the single attribute. |
tp | Attribute's type | The type of the single attribute. |
vals | Values area of the attribute. | Values area of the single attribute. |
names | The names of the attribute's values for the selective type. | The names of the single attribute's values for the selective type. |
| Team request command of the all values of attributes of the parameter: <get path="/sub_DAQ/mod_{SRC}/cntr_{CNTR}/prm_{PRM}/%2fserv%2fattr"/> | ||
| <el id="iatr">val</el> | Attributes' values | In separate tags the values of the attributes are returned. |
| The set command of the the values of the specified attributes of the parameter: <set path="/sub_DAQ/mod_{SRC}/cntr_{CNTR}/prm_{PRM}/%2fserv%2fattr"/> | ||
| <el id="iatr">val</el> | The values of attributes are specified | In separate tags the values of attributes are specified. |
To request the archive data in the archiving subsystem of the messages archive's object the following command is provided <info path="/sub_Archive/%2fserv%2fmess"/> и <get path="/sub_Archive/%2fserv%2fmess"/> to request the information about the archive and archive's values respectively. The detailed description of these commands is presented in Table 24.
Table 24. Attributes of request commands of information about the archive of values and archive data
| Id | Name | Value |
| Request command of the information about the archive: <info path="/sub_Archive/%2fserv%2fmess"/> | ||
| arch | Setting the name of the archive's archiver | Archive's archiver, for which to specify the parameters. |
| end | Control of the archive's top in the given archiver | As a result of the request points to the real top of the messages' archive in the given archiver <arch>. |
| beg | Control of the archive's depth in the given archiver | As a result of the request points to the real depth of the messages' archive in the given archiver <arch>. |
| Request command of the archival and/or current data: <get path="/sub_Archive/%2fserv%2fmess"/> | ||
| tm | Time set | Time of the block's top of the messages' archive . |
| tm_grnd | Time set of the foundation/beginning of the archive | Points to the foundation/beginning of the archive. |
| arch | Setting of the archive's archiver | Specifies at what archiver to request the values. If the archiver is not specified, the request will be made consistently in all archivers with the exception of duplicates. |
| cat | Setting the message's category | Specify the category/template of the requested messages. |
| lev | Setting the level of importance | Specifies the importance level of messages for which and above to get the messages. |
| <el>mess</el> | Messages | In separate tags the messages are returned. |
time | Message's time | Time of the separate message. |
cat | Message's category | Category of the separate message. |
lev | Message's level | Level of the separate message. |
To request the archive data in the archiving subsystem of the values archive's object and parameter's attribute object of "Data acquisition" subsystem the following command is provided <info path="{a_p_addr}/%2fserv%2fval"/> и <get path="{a_p_addr}/%2fserv%2fval"/> to request the information about the archive's and archive values respectively. Attributes of these commands, involving various mechanisms of the request are presented in Table 25.
Table 25. Attributes of the request commands of information about the archive of archive data