IDEC WindSRV - Manual (Page 20)

19
www.kepware.com
KEPServerEX5 Help
automatically generated. Descriptions of the selections are as follows.
 Do not generate on startup, the default condition, prevents the driver from adding any OPC tags to the tag
space of the server.
 Always generate on startup causes the driver to evaluate the device for tag information and to add OPC tags
to the tag space of the server every time the server is launched.
 Generate on first startup causes the driver to evaluate the target device for tag information the first time the
project is run and add any OPC tags to the server tag space as needed.
Note: The Auto-Create button will be disabled when the Configuration edits a project offline.
When the option to automatically generate OPC tags is selected, any tags that are added to the server's tag space must
be saved with the project. Users can configure the project to auto save from the Tools | Options menu.
Perform the Following Action
When automatic OPC tag database generation is enabled, the server needs to know what to do with OPC tags that it
may have added from a previous run or with OPC tags that have been added or modified after the communications
driver added them originally. The Perform the following action setting is used to control how the server handles OPC
tags that were automatically generated and currently exist in the project. This feature also prevents automatically
generated tags from accumulating in the server.
For example, review the Ethernet I/O example mentioned above. If users continued to change the I/O modules in the
rack with the server configured to Always generate new OPC tags on startup, new tags would be added to the
server every time the communications driver detected a new I/O module. If the old tags were not removed, many
unused tags could accumulate in the server's tag space. The Perform the following action setting allows users to
tailor the server's operation to best fit the application's needs. Descriptions of the selections are as follows.
1. Delete on create, the default condition, deletes any tags that had previously been added to the tag space
before the communications driver adds any new tags.
2. Overwrite as necessary instructs the server to remove only those tags that the communications driver is
replacing with new tags. Any tags that are not being overwritten will remain in the server's tag space.
3. Do not overwrite prevents the server from removing any tags that had been previously generated or may have
already existed in the server. With this selection, the communications driver can only add tags that are
completely new.
4. Do not overwrite, log error has the same effect as the third; however, in addition, an error message will be
posted to the server's event log when a tag overwrite would have occurred.
Note: Removing OPC tags affects tags that have been automatically generated by the communications driver as well as
any tags that have been added using names that match generated tags. It is recommended that users avoid adding
tags to the server using names that match tags that may be automatically generated by the driver.
The parameter Add generated tags to the following group can be used to keep automatically generated tags from
mixing with tags that have been entered manually. This parameter is used to specify a subgroup that will be used when
adding all automatically generated tags for this device. The name of the subgroup can be up to 256 characters in
length. The following screens demonstrate how this parameter works, i.e., where automatically generated tags are
placed in the server's tag space. As shown below, this parameter provides a root branch to which all automatically
generated tags will be added.