An application built with PI-API-NT looks for the initialization file called pilogin.ini and for the file piclient.ini. These files contain server and port information to support default connections and connection to multiple PI Servers. The piclient.ini file is now used to configure API buffering.
The PI-API library uses several methods to find these files. First it checks the dat subdirectory under the directory defined by PIPCSHARE in the pipc.ini file. Next it checks in a directory up one level and back down into a directory called dat from the current directory. If not found there, the directory specified as PIHOME above is used as the current directory and its dat subdirectory is searched. Other locations are also searched for backward compatibility, but it is advisable to have a single instance of these files in the primary location.
The piclient.ini file has historically been used to support the definition of the default server. The pilogin.ini file was introduced with the PI-ProcessBook program to support both default connections and multiple connection management. The file now also supports port definition and node ID’s (a numeric mapping of server nodes used to reduce storage and provide server and application mobility).
Currently the PI-API will search for either of these files for connection information. The pilogin.ini is preferred, and if found will be used. The piclient.ini file is supported for backward compatibility. Typical .ini files are shown below. During installation, a sample pilogin.ini is installed in the PIHOME\dat subdirectory and may be edited to reflect the user’s servers and login names as described below.
The standard .ini file format is composed of sections (surrounded by brackets), items or keys (to the left of an = sign) and values (to the right of an = sign). All lines beginning with a semicolon (;) are comments only.