Server Configuration

The server can be configured through several class attributes. These attributes can either be overridden in the inheriting object, or can also be specified at the server object instantiation.

The basic XDAServer class provides the following options. (Their default values are given in parentheses.) Some of them are are further described in later sections:

AutoItemCache (True):

This option enables the automatic OPC item caching.

WritePurgeCache (True):

Denotes if the item cache should be flushed after an item is written.

DefaultMaxAge (1000):

The default maximum age of an item.

BufferSize (100):

The default subscription buffer size in number of items.

ThreadedParsing (True):

One of the most CPU-intensive tasks is the parsing of the incoming SOAP message. In order to speed up the server, it is possible to execute the parser in a separate thread, so that the server can execute other requests in parallel¹⁴.

ThreadPoolSize (5):

The maximum amount of concurrent threads.

SubscriptionPingRate (10000):

The default subscription ping rate in milliseconds.

MaxPingRate (86400000 = 1 Day):

The maximum ping rate that may be specified by a client.

MaxSamplingRage (100):

The maximum sampling rate in milliseconds that clients may specify.

HandleProperty_value/quality/timestamp/scanRate (True):

Denotes if the above properties are automatically generated/handled.