Seamless vs 800xAHistory "Log Name"
I have two systems here each pulling data from similar, underlying OPC DA/AE sources.
Now... the log configs and trends on both are configured the same... as far as I can see...
I guess there must be something different, though, because...
One one system the trends work fine as they are configured.
On the other, they dont...and as far as I can tell... they are set up the same.
The symptoms present as a constantly changing data history set of two states, either offscale or zero, so that they look kind of like boolean trends, but are, in fact analogue.Setting the upper limit of the range to very large values has no effect, in terms of bringing the trace into view.
The data set changes regularly and is apparently random... some times high frequency, sometimes a single step, or only a few up/downs...
For the system that doesn't wqork, I've found that when you first open the trend, momentarily, the range is set to the range matching the Log configuration's 800xAHistory Log "Presentation" tab.
(for the working system this range loads and sticks)
Within a second it is set to -100 to 100%... and the odd behaviour ensues...
If I force the trend "log name" field from the default "SEAMLESS" to "800xAHistory", The "presentation" range is set and the data appears.
If I go back to "SEAMLESS"... it goes back to the -100 to 100% behaviour.
If I force to "TRIM" it holds whatever range was last set and begins tracing at the far right as you would expect... if it's held the range from SEAMLESS mode and the value is inside the range -100 to 100 it is visible.
Since I cant find anything that appears differently configured between the two systems, I'm hoping someone will recognise these symptoms and point me in the right direction to find the difference.
What connect family are you making use of?
Many connects (800xA for Advant Master, AC 800M Connect, PLC Connect, etc) have built-in support for automatic retrieval of the presenation attributes (min, max, no of dec and engineering unit),
800xA for Advant Master uses, Control Connection and Additional Info
AC 800M Connect has built-in support for scaling of RealIO variables
PLC Connect has presentation info settings available in the configuration
If your choice of connect does not have any support for presentation attributes you can still create your own definition by using the Property Extension Info aspect.
A last resort can be to hard code the settings on the Log Configuration (each log may have its own setting so a large Log Template with many logs is more complex than a template with only one log).
The trend can override min and max.
A random mixture of the above methods and overrides is often a recipe for problems...
Please inject more info...
How are you mate ? Long time no see.
If it looks like its configured right, and setting it to 800xA history makes it work properly then I guess the data is getting logged properly ?
Basic troubleshooting for this kind of thing is Restartng the history services ( one server at a time ) to force everything to resynch and checking the data with the "read" function on the log configuration.
I think when you go to "seamless" the trend configuration goes to the ranges held in the secondary log. Check to see if anyone over-rode these.
If you still cant find anything wrong, deleting the log and creating a new log config can often fix odd things like this. ( you might need to restart history services again )
As you have indicated that this is 800xAHistory, what version are you running, 2.0 RU2 is the most current version, and there may be TC's that may be appropriate to install, depending on your configuration.
Have you checked vTrin in both the DCN(s) and History Server(s) nodes to verify that the data is correct. There is a Trend function in vTrin that may provide some more insight as to the problem.
If you look at this information and still cannot find the answer, it may be best to open a Support Case with your local RAC to see if there are other issues.