Applies To:
  • CitectSCADA 2.00 2.01

Question: I have 15 DspSymAnm on one page and the performance of Citect is very slow. What is causing this problem? 

In version 2.xx the function DspSymAnm was changed to reference symbols by names rather than numbers in version 1.xx. This caused increased overhead with this function causing slower updates and increased loading on the CPU. In version 3.xx and later this function has been highly optimised to reduce the overhead associated with referencing symbols by their names. To reduce the loading on your CPU you should upgrade to version 3.00 or later or reduce the calls to DspSymAnm.

You may reduce the calls to DspSymAnm by only calling this function when the values of the arguments changes. For example if you are calling this function in the Advanced Animation and the arguments never change, you can change your code as follows:

IF PageInfo(7) = 0 THEN DspSymAnm(21, "symbol.name2", "lib.name2"); END;

PageInfo(7) will return 0 when the page is first displayed (see Q1395) and so DspSymAnm will only be called once for this page. You only have to call the DspSymAnm() function and the symbols will continue to be animated in the background. If the arguments to DspSymAnm() change under some condition you only have to call this function when the arguments change. This will reduce the loading on your computer.