I have always wanted a way to turn register space in a PLC into a data logger or trend recorder. It would be nice to have a feature to display this stored data using a iPod or iPad when I walk up and connect to a local PLC. It would take some coordination between the PLC and the display since sample time would need to be matched. Once per minute, once per day, once per week, etc. The good thing about it would be that a PLC could record historical data that could be easily viewed when you walk up to it and connect. You would not have to wait for the data trend to develop on your conneted device.
It would also be good to be able to store and display bool data such as pumps on/off and display it along with analog values such as level.
On the next release -due in less than a week- we are adding a chart object and a data snap object that combined together could serve for what you describe.
The data snap object is designed to read -once- a series of data from the PLC, based on a custom trigger that you define such as an user button press. Then you can represent this data on a chart object.
On the chart object you can represent several series of data and you can define custom labels -even programmatically- for each entry. The labels can also be automatically generated according to a starting value and an incremental offset, which probably covers all possible needs. Chart values can be presented as lines or bars.
Finally, there should be no issues on presenting boolean data along with analog data because you can simply scale your bools before presenting on a chart to make them appear at a particular height on the chart.
For this to be easier your data in the PLC should be contiguous. Also you should keep separate tag sets for minute data, day data and week data. I assume you already do so.
Please give me more details on what is your idea on how this should work, in case this does not answer your question.