Note: The disconnected startup feature can not be used if the interface is using the PI SDK to retrieve extended point attribute information for points from the PI Server. Either disable the PI SDK by defining /pisdk=0 in the startup command file or remove any disconnected startup parameters from the interface startup command file. Failure to implement one of the preceding options with the PI SDK configured to retrieve point attribute information will cause the interface to log an error message in the pipc.log file and then shutdown.
Some UniInt interfaces are designed to require the use of the PI SDK to retrieve point information if the PI API is less than version 1.6 and/or the PI Server version is less than 3.4.370.x. In this case, setting the /pisdk=0 startup command-line parameter may not disable the PI SDK and prohibit the use of the disconnected startup feature.
There are two interface startup parameters that control the disconnected startup operation: /CacheMode_and_/CacheSynch'>/CacheMode and /CacheSynch. Each of these parameters is described in the following table.
Required for disconnected startup operation. If defined, the /CacheMode startup parameter indicates that the interface will be configured to utilize the disconnected startup feature.
/CacheSynch=# Optional
Default: 250 ms
NOTE: Care must be taken when modifying this parameter. This value must be less than the smallest scan class period defined with the /f parameter. If the value of the /CacheSynch parameter is greater than the scan class value, input scans will be missed while the point cache file is being synchronized.
The optional /CacheSynch=# startup parameter specifies the time slice period in milliseconds (ms) allocated by UniInt for synchronizing the interface point cache file with the PI Server. By default, the interface will synchronize the point cache if running in the disconnected startup mode. UniInt allocates a maximum of # ms each pass through the control loop synchronizing the interface point cache until the file is completely synchronized.
Synchronization of the point cache file can be disabled by setting the value /CacheSynch=0. The minimum synchronization period when cache synchronization is enabled is 50ms Whereas, the maximum synchronization period is 3000ms (3s). Period values of 1 to 49 will be changed by the interface to the minimum of 50ms and values greater than 3000 will be set to the maximum interval value of 3000ms.
Default: 250 ms
Range: {0, 50 – 3000} time in milliseconds
Example: /CacheSynch=50 (use a 50ms interval)
