WinCC Trending

[JDCROCKETT724]

I am trying to start and stop a trend via a tag from the PLC. I have 8 things happening at once and would like to have all 8 things independently trending on their own screen. Setting up the trend isn't the problem, but I need to be able to start and stop it so the trends can be reviewed easily if they need to be analyzed. Does anyone know how to do this?

 

[JDCROCKETT724]

Bump. I was thinking maybe a script could do it by accessing the internal HMI tags, but I have no experience with scripts. Does anyone know where I could find a list of all internal parameters on the Comfort Series HMI's?

 

[JDCROCKETT724]

Anyone have an idea on this. I was thinking I could use a data log, but I can only sample at 1 second intervals in the data log. I need to sample at 10ms for only 10 seconds. There has got to be a way to do this...

 

[JRW]

Unfortunately you will not get updates that fast to the hmi
But
You could buffer in a data block then bring it out to hmi

The next question is how much data to buffer?

 

[CharlesM]

I have an array in the plc that i use to capture the data. By using 4 arrays of the same size i copy one to the next at the start of the cycle so i index all the data down and the oldest cycle drops out and i write the current cycle to the first array. Then i use buffer bit trends to load them to the hmi for viewing

 

[JDCROCKETT724]

Thanks. It looks like the buffer is the way to go.