Applies To:
  • CitectSCADA 5.xx, 6.xx
  • CitectHMI 5.xx, 6.xx

Improvements have been made to the the Kingfish driver regarding event data and the control of data retrieval requests.

1) The function BuildRequest() has been modified to check for event data more often.
2) Several ini parameters have been added to control the priority and timeouts of data retrieval requests. These are the new INI Parameters and their default values:

EventCheckPeriod = 2000 (Milliseconds)
IntegrityPeriod = 10000 (Milliseconds)
UpdateCounterPeriod = 1000 (Milliseconds)
DriverScanPause = 100 (Milliseconds)

The explanation of each parameter are as follows:

EventCheckPeriod (Default = 2000mSec)
This value controls the rate at which the driver requests events from the RTU.

IntegrityPeriod (Default = 10000mSec)
An attempt is made to periodically refresh the cache at this rate in order to ensure its integrity. However, this is dependant on transmit loading from RTU Read/Write requests and event downloads. If a cached value is older than 3 x IntegrityPeriod, the cache read will be escalated to an RTU Read.

UpdateCounterPeriod (Default = 1000mSec)
Controls the rate at which Cupdate register (register 2 of Network Link Info 2) and Cfail register (register 4 of Network Link Info 1) requests are made.

DriverScanPause (Default = 100mSec)
Enforces idle time between processing next transmit.  A transmit may be from a non-cache Read, Write, Event Refresh, Cache Refresh, or Register refresh.

These INI parameters do not have fixed ranges and judgement should be exercised in order to set best values for the given application and circumstances rather than adjusting to maximise. 


Kingfish, driver, ini, citect.ini, parameters, EventCheckPeriod, IntegrityPeriod, UpdateCounterPeriod, DriverScanPause, Event Data, Data Retrieval