The Rockwell Automation RSView32 source data tested where in dBase IV files with long and short file names. The files are in pairs; one contains the tag names and indexes and are identified by "Tagname" or "T", and the other file pair contain data and are identified with "Wide" or "W".
A long file name for tags looks like: 2009 07 01 0000 (Tagname).DBF and would be the same in short form as 090702AT.DBF
A long file name for data (WIDE) looks like: 2009 07 01 0000 (Wide).DBF and would be the same in short form as 090702AW.DBF
The Hach WIMS Indirect Server-Side Interface to Rockwell RSView32 connects to these files using the Microsoft Jet OLEDB driver. In order to connect to these files, Microsoft Jet requires the file names to be in the short format. All data files are copied to a folder under the Hach WIMS interface application and renamed to the short format if necessary. Here is an example of a connection to Microsoft Jet:
Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\Data\EMC-WWTP;Extended Properties=dBASE IV;User ID=Admin;Password=;OLE DB Services =-2;
The main data point for dBase IV files is C:\Data and our node is EMC-WWTP. The node is a feature in Rockwell RSView32 that allows various tags to be collected in different folders under the main data point. So, in our example we might have EMC-WWTP, EMC-WWTP-02, and EMC-WWTP-03. We might have the same tag name under each node because the tag name pertains to a specific device in different locations.
Both Tagname and Wide files are need to gather data. The Tagname file tells us the index of that tag. The Wide file contains data in a wide format, columns correlate to the tag index. For example:
We want to get data for the tag IND\IND_DO_0201. The Hach WIMS software will query the Tagname file to find the index:
Next, the system looks up the data based on that TTagIndex field:
The values under that TTagIndex column are captured, summarized, and imported in to the Hach WIMS Client database. Notice that we queried the previous day's file for 7/2/2009. This is because, in our testing we discovered that, just past midnight, the previous day's file is closed and a new file is created for the current day. The system does not stop gathering data in the process, and therefore some of the data for the current day was written to the previous day's file.
The format for Hach WIMS client variable definition is NODE:TAGNAME. In order to properly identify this data point in Hach WIMS client, we attach the node to the tagname and get:
EMC-WWTP:IND\IND_DO_0201