Grissess: Created page with "The Digital Display is a block which displays fine values on a signal cable at a point in time. Like the Wall Clock, it can be colored with a Brush. The UI allows..."

2020-06-01T11:58:51Z

Created page with "The Digital Display is a block which displays fine values on a signal cable at a point in time. Like the Wall Clock, it can be colored with a Brush. The UI allows..."

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The [[Digital Display]] is a block which displays fine values on a signal cable at a point in time. Like the [[Wall Clock]], it can be colored with a [[Brush]].

The UI allows adjustment of the value displayed at 0V (0.0) signal and 50V (1.0) signal; by default, the range is 0 to 1000, matching the default RPM readout of the [[Tachometer]]. The value displayed can be any between 0 and 9999, and will clamp to that range.

When looking at the digits upright, the input side is the bottom. The sides have a common "strobe" input, that, when >=0.5, turns off all digits. This is typically hooked up to a square wave generator to "flash" the digits. Sides from adjacent displays will connect, allowing a line to be strobed at the same time, much like [[Nixie Tubes]].

The top input has the "dots" control; there are five dots along the bottom of the display, and three colons between each two digits. These can be used, e.g., to indicate durations, or auto-scale the display. Since there are 8 possible indicators, the range of values is evenly broken into 256 intervals, where 0 displays no dots and 1 displays every dot and colon; each interval is of size 1/256. You can, e.g., put some <code>N/256</code> into a [[Signal Processor]] to generate the value, where N is the sum of the following values:

{|class="wikitable"
! Value !! Dot/Colon
|-
| 1 || Rightmost dot
|-
| 2 || Second rightmost dot
|-
| 4 || Center dot
|-
| 8 || Second leftmost dot
|-
| 16 || Leftmost dot
|-
| 32 || Rightmost colon
|-
| 64 || Center colon
|-
| 128 || Leftmost colon
|}

For example, use <code>8/256</code> (or <code>1/32</code>) to make the "thousands place" dot appear, use <code>64/256</code> (or <code>1/4</code>) to make the center colon appear for time readouts, use <code>31/256</code> to turn on all dots (but not colons), etc.

As you might be able to guess, N is a binary-encoded integer of 8-bit width where the LSB is the rightmost dot, progressively more significant from right to left, and jumping to the colons, where the leftmost colon is the MSB.

== Usage ==

Although [[Data Logger]]s are particularly accurate, their rasterization often prevents them from representing both large ranges and having good precision, which often leads to having two data loggers (a coarse and fine one) per steadily-monitored signal. Unfortunately, data loggers are both graphics- and network-intensive, so this approach does not scale well. (Data loggers, however, are still essential to seeing change over time.) If a signal's past values are less important than its current value ''to high precision'', a [[Digital Display]] is appropriate.

For example, connecting a digital display to a [[Tachometer]], with both default settings, will give a reading of the shaft speed down to the RPM. (You can set the display range to 0 to 9999 and the tachometer range to 0 to 999 to get a display in terms of deciradians/second; sending in <code>2/256</code> or <code>1/128</code> to the "dots" input on the top will also show the radix point.) Connecting to an [[Electrical Probe]] can give up to four magnitudes of precision on any metered value, such as a kilovolt cable down to the volt, or amps down to the milliamp.

When using the Digital Display, it is important to make sure your ranges are synchronized. The [[Config Copy Tool]] can help you harmonize these ranges, since the min and max bounds are shared between all the probes, the data loggers, and the digital display. (Units are additionally shared between probes and the data logger.) Just copy from the (configured) probe and paste on the display (or logger).

Digital Display - Revision history

Grissess: Created page with "The Digital Display is a block which displays fine values on a signal cable at a point in time. Like the Wall Clock, it can be colored with a Brush. The UI allows..."