Displaying Graphics in QNX

Graphics are not currently loaded by default when HCHO algorithms are initialized; however, they can be easily set up using the PhRTG Console window. The variables that can be plotted are listed under the Variables tab.

Three Common Graphics

1. The first graphics window contains power-normalized scans, which is useful to see quickly at a glance the positioning of the online and offline positions. The variables constitute this window are ScanNorm0 and ScanNorm1.

2. The second graphics window contains three separate plots that each have their own pane. I generally have plotted the reference PMT signal (BCtr_0) on the top pane, the input power meter signal (LasIn_mW) on the middle pane, and the sample cell PMT signal (BCtr_1) on the bottom pane.

3. The third window contains hcho_mr which provides a rough estimate of the HCHO mixing ratio. Even if the cal factor is known to be wrong, this window can still show trends in the mixing ratio over time.

FAQs

Q1: Can tick marks or labels be placed on the x or y-axes?

A1: At the present time, this feature is sadly not available in QNX. As a rough guide, you can get the maximum and minimum x or y values by going to the PhRTG Console window and clicking on the X or Y tabs.

Q2: Can the speed at which the x-axis moves be sped up or slowed down?

A2: Yes, click on the plot you want to change and go to the X tab located in the PhRTG Console window. Then, change the number next to the Trend option to either speed up (lower numbers) or slow down (higher numbers) the x-axis.

Q3: Can I change the line color from blue so that it's easier to see on my monitor?

A3: Yes, click on the plot you want to change color and go to the Line tab located in the PhRTG Console window. Green and white are generally easier to see than the default blue color.