TRENDS - HMI

Trend

Trend is a graphical representation of value(s) over a period of time. Trending allows you to view data sampled over a time period in a graphical display. Data is sampled at a periodic rate. You can trend objects with different update rates or with the sample update rate simultaneously. You can also configure events to trigger the start and stop of data logging, and collect data samples to analyze offline.

Trend Types

There are two types of trends: Real Time trends and Historical trends.

Real time trends are dynamic. They are updated continuously during runtime.

Historical trends provide a snapshot of data from a time and date in the past. They are not dynamic. Unlike real-time trends, historical trends are only updated when they are instructed to do so either through a logic of when the operator click on a button.

Historical trend gives the operator a complete flexibility in designing the interface to your trend. You can create scooters that the operator slides over the trend to access a variety of data based on the scooter's current location. For example, when the operator positions the scooter over an area on the trend that has visible data, the time and values at that location for all database values being trended is returned to you. You can also create buttons to zoom in and out between the scooters or to data, such as the maximum to minimum value. Average and standard deviation can be displayed for the complete chart or for the area between the scooters. Historical trends can also be scrolled by any amount of time.

Distributed Trends

There exist even distributed history system that extends the retrieval capabilities of historical trends to include remote log databases. This system allows information from multiple historical log databases to be displayed in a single trend.