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

I am using Unite driver and my graphics pages are taking too long to update or display. It can take up to 5-10 secs.

The following can be used to improve the UNITE driver performance:

1) Decrease the PLC scan time to 80ms or 10ms (i.e. A faster scan time). A PLC processor with a fast scan time has a significant communication performance advantage over a processor with a long scan time when the UNITE driver is being used.
2) Set [UNITE]Block=120. This should have about a 20% improvement in performance.
3) Set Cache time in the IO device form e.g. to 600ms.

Alternatively you can convert to using the MODNET driver which will have a better performance than UNITE due to larger block size and concurrent data request.

Slow, Unite, Page