Applies To:
  • CitectSCADA 1.00, 1.01, 1.10, 1.11, 1.20, 2.00, 2.01

Question: I have setup a CINET network and everything works OK except for the trends. What could be causing this problem? 

Trend displays uses the greatest amount of network traffic because many thousand variables must be transferred from the trend server to the client (to display the trends). Because of this, any problem will be likely to show up first with the trend displays. The trends may not display correctly if the CINET is not installed correctly or the network is overloaded.

Make sure the network buffers are tuned correctly, see Q1131 for details. This will fix most problems with the installation of CINET.

You may be overloading the network with too much data. This can happen if the baud rate is too low, or the trends have too much data. Each sample point you display on a trend takes 2 bytes of network traffic plus extra protocol overhead. If you have 8 pens x 300 samples x 4 trends, you would have around 20k of network data. At 9600 baud, it would take over 20 seconds to transfer the data.

You should try to run CINET at the fastest possible baud rate.

You can also reduce the trend data by changing the trend display. The standard trend templates display a large amount of samples, pens and trends. You may want to create your own trend template that uses less samples (eg display 100 samples, rather than 300 - this will give 3 times better performance). You can also reduce the number of pens on the same trends, (display one or two pens rather than eight), and reduce the number of trends on the page (display one trend rather than 4).