| Applies To: |
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| Summary: |
| Typically we associate Tag Based Drivers
with OIDs, but not all of Citect's Tag Based Drivers use OIDs.
Special care and understanding is required when using these
drivers.
Non OID Tag Based Drivers access the Variable.dbf, however deleted records in a dBase file do not get physically deleted until the database is packed. As a result, a Citect variable tag may reference the wrong address if deleted records exist in the Variable.dbf's in the main or any included projects. Reference Tag Based Driver - The tag address field references a name within the PLC, not a numeric address. OID Driver - Drivers which use the combination of Project ID & record number to reference the tags. Can be identified by %J and %K in driver dbf file. Non OID Driver - Older drivers which use the record number in the variable.dbfs to reference the tags. Can be identified by %R, %N & %N+ in the driver dbf file. |
| Solution: | ||||||||||||||
| When using any of these Non OID Tag Based
Drivers you MUST ensure that all of the following criteria are met:
The variable.dbfs in the main AND all include projects have been packed The variable.dbfs on all Citect PCs are identical (i.e.. same tag order) The Include project order on all Citect PCs is identical It is important to understand that this is the case for all projects using these drivers, whether standalone or networked and with or without included projects. The easiest way to pack all included projects and check the project include order is to use the Project Pack Utility which can be downloaded from the Database Tools section of the Citect Toolbox. Following is a list of the Non OID Tag Based Drivers:
(* Note: TPERM is a hybrid tag/address based driver) Note also that some of the very early Non OID Tag Based Drivers also require that ALL tags are defined in the main project. These are DDEDRV, OPTOMIST and STEEPLE. |
| Keywords: |
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