We have a SCADA system with 8 ABB AC410, 5 AC110, 2 AC70,a report station and two operator stations.

One of the AC410 is about 200m away from control room, 6 of AC41O are distributed to different process with 5 of them having additional AC110 (AVR COMPUTERS). 2 have additional AC70. One AC410 is located in control room and its the station computer also connected to a report station that displays trends from process AC410 in excel. The two operator stations are AS500 from ABB and each has an event printer also located in control room. We have five generators each with AC410 as the generator PLC and AC110 as the AVR PLC but generator 4 and 5 have additional AC70 for their auxilliaries.

The problem we are facing is that the trends on the operator station for generator 2 - 5 are broken and disappear after every 30 mins on the operator station and the trends for generator 1 (which is closer to control room ) are ok and don't disappear. The head and tailrace water levels are read from the station computer and also do face the same problem.

We have MB300

 

On AS500 Stations all trending is done using TTD Logs. So the trend data must be read from an AC410 controller whenever a trend display is opened on the AS500. I cant suggest an immediate answer as there are many possible causes. However, if you have MB300 problems they should be pretty obvious from the system message list. its more likely that you have a problem in the controller or RTA board tasks.

When you say the trend disappears, what exactly are you seeing ?

- Are there gaps in the trend data every 30 minutes or do trends that were working disappear from the display ?

- Does the problem occur when you try to open a trend display or after a display has been open for 30 minutes ?

- Are you getting any System Error messages on the AS500's

- Are you getting any error messages when you connect to the AC410 controllers with on-line builder ?

- How are you getting data from the AC410 controllers into Excel for trending?

- What version of Advant Software are you running on the AS500's ?

- Check the CPU loads on the AC410 controllers.

Rob
www[.]lymac.co.nz