Broken Trends on MMI

Good time of day waco,

I suppose your data is logged somewhere else like db or even delimited text file. Therefore you would get this data and treat it through stand alone software (MS Exell) for drawing graphic trend. If you'll get the same dashed graphs --- there is problem with lost data, if there will be smooth, good looked graphics --- your Scada ActiveX trend building component is working wrong.

Regards.

Hi,

First question, what brand of MMI are you using and are you using the a real time or historical trend display object in the MMI or an external client tool?

Next thing is to check the tags that are in the trend, are they periodic (cyclic) or delta (logged on change)? Is the data connection being lost briefly? Check the log files of the MMI if they are available, and the IO server log files if they are available. Also how is the data retrieved, this may seem not relavent but if the network to the control system is heavily loaded data may drop out.

Cheers,

Trevor.

Check your MMI and operating system software DATA polling and phasing sequence configuration settings. The system may be trying to poll too many tags/devices within the same time frame or may not be polling the DATA source fast enough. If you do not organize and schedule these components of DATA interrogation properly in a SCADA system, you will suffer DATA losses. Sometimes it is advantageous to develop a spreadsheet or other type of hardcopy sheet listing the DATA blocks in sequence so that the DATA polling timing development relationship can be seen and understood. Determine the SCADA machine scan time and your system communications speed relationship, then schedule the events accordingly staying within the confines of the system comm. bandwidth limitations. Make sure that your system design allows enough "headroom" to accomodate the number of devices attached to your system while providing simulataneous DATA interrogation and reporting.

Also, a very important dynamic to consider when developing your polling record and system configuration is the amount of system memory available in the node, the type of memory, and the OS (operating system) processing speed. If too much of the available memory is being consumed for the higher priority operation of the system, the DATA gathering will (should) be "set aside" during those periods of time.

If you cannot solve the issue by following these guidelines, contact the MMI software OEM and follow their recomendations. If that does not work, set up a continous ping for active nodes in your system or use a spectrum analyzer to diagnose your system communications integrity. Look for any device on the system that might be in a "runaway" broadcasting state and "hogging" the bandwidth.

I hope this helps. Good luck!

Thanks guys

Reply to Tooz, our MMI is nokia and its kind of accient type ,am gona do all u said and i will let you know of any changes.