<div dir="ltr">As I continue to study the APRS symbol set this year, I've noticed a set of symbol overlays indicating the power source for APRS stations, but their documented application is limited to only a few base symbols and is somewhat sporadic. Houses get all sorts of options for symbol overlays indicating their power, but shelters get none. <div><br></div><div>In an effort to free the symbol overlay from trying to indicate both the type of station and the type of power source for the station, I'm proposing a new data extension to indicate power source. </div><div><br></div><div><div class="gmail_signature">Thoughts?</div><div class="gmail_signature"><br></div><div class="gmail_signature">Why was 50Hz vs 60Hz handled for houses? I'm a bit at a loss where that would be an issue.</div></div><div><br></div><div><a href="https://github.com/PhirePhly/aprs_notes/blob/master/power_capability.md">https://github.com/PhirePhly/aprs_notes/blob/master/power_capability.md</a></div><div><br></div><div><h1 style="box-sizing:border-box;margin:0px 0px 16px;line-height:1.25;padding-bottom:0.3em;border-bottom:1px solid rgb(238,238,238);color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol"">Power Source Data Extension</h1><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">There has been a proliferation of APRS symbol overlays trying to encode the power source for stations, which suffers from a few issues:</p><ol style="box-sizing:border-box;padding-left:2em;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><li style="box-sizing:border-box">Several duplicated sets of symbol overlays for power sources per station type (i.e. solar powered plane, solar powered car, and solar powered house)</li><li style="box-sizing:border-box;margin-top:0.25em">Prevents the symbol overlay from being used to convey more important information than the station's power source</li><li style="box-sizing:border-box;margin-top:0.25em">Is unable to represent more than one power source at a time</li><li style="box-sizing:border-box;margin-top:0.25em">Only gives the ability to indicate power source to a limited list of station types which have symbol power overlays defined</li></ol><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">To correct these issues, I am proposing the definition of a new station capability field to be included in the <code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px"><</code> capability packet or included as a data extension in location or status comment fields.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=[Unordered list of power source codes]</code></p><ul style="box-sizing:border-box;padding-left:2em;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><li style="box-sizing:border-box">B - Battery</li><li style="box-sizing:border-box;margin-top:0.25em">C - Coal, natural gas, wood, etc</li><li style="box-sizing:border-box;margin-top:0.25em">F - H2 fuel cells</li><li style="box-sizing:border-box;margin-top:0.25em">G - Internal combustion generator</li><li style="box-sizing:border-box;margin-top:0.25em">H - Hydroelectric</li><li style="box-sizing:border-box;margin-top:0.25em">N - Nuclear</li><li style="box-sizing:border-box;margin-top:0.25em">S - Solar</li><li style="box-sizing:border-box;margin-top:0.25em">T - GeoThermal</li><li style="box-sizing:border-box;margin-top:0.25em">U - Utility mains</li><li style="box-sizing:border-box;margin-top:0.25em">W - Wind</li></ul><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">Multiple sources should be listed as several power source codes immediately following the <code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">=</code> with no seperator between power source codes. The list of power sources is terminated by any character which is not an upper case letter [A-Z].</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">The PWR extension is not meant to differentiate between different sources for utility mains power. The availability of power codes such as geothermal and nuclear are only for completeness, and should not be used by stations which are simply paying their local utility company to operate these sorts of power sources. This means that a power source like <code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=N</code> would be very unusual, since it indicates that the station is operating a nuclear power source.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">Stations should indicate the power sources they typically have available, which may not currently all be active. For example, an off-the-grid solar site would beacon <code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=SB</code> to indicate that they are a solar + battery station, despite the fact that the solar panels aren't necessarily producting power during the night.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">This means that the PWR extension should never be used as a way to remotely monitor power sources like whether a site has utility power or not (i.e. it switching between <code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=UB</code> and <code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=B</code>). The correct way to monitor if a site has power or not is to use one of the boolean telemetry fields to encode the power state and beacon a telemetry formatter such as <code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">:MYCALL :PARM.,,,,,AC Power</code>.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">The PWR extension may be foregone when the power source for a station is unremarkable. For example, house stations only running on wall power (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=U</code>) or car mobile stations only running on internal combustion generator (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=G</code>) may forego the additional packet length taken to indicate the obvious.</p><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">This power source capability / data extension field deprecates the following symbol overlays (with possible replacements indicated):</p><ul style="box-sizing:border-box;padding-left:2em;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px"><li style="box-sizing:border-box">E^ = Electric aircraft (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=B</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">S^ = Solar powered airplane (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=S</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">E> = Electric car (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=B</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">H> = Hybrid car (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=BG</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">S> = Solar powered car/vehicle (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=S</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">V> = GM Volt (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=BG</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">E# = Emergency powered digipeater (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=?</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">5- = 50Hz mains power, house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=U</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">6- = 60Hz mains power, house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=U</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">B- = Backup battery power, house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=UB</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">E- = Emergency power, house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=?</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">G- = Geothermal, house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=T</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">H- = Hydro powered, house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=H</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">S- = Solar Powered, house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=S</code>)</li><li style="box-sizing:border-box;margin-top:0.25em">W- = Wind powered, house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=W</code>)</li></ul><p style="box-sizing:border-box;margin-top:0px;margin-bottom:16px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px">Many of these symbols would likely be replaced with something other than what's listed; e.g. the overlay for a solar-powered house lacked the expressiveness to distinguish if it's a grid-tied solar-powered house (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=SU</code>) or if it's an off-the-grid house with a battery bank (<code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=SB</code>).</p><p style="box-sizing:border-box;margin-top:0px;color:rgb(51,51,51);font-family:-apple-system,blinkmacsystemfont,"segoe ui",helvetica,arial,sans-serif,"apple color emoji","segoe ui emoji","segoe ui symbol";font-size:16px;margin-bottom:0px">The distinction between 60Hz utility power and 50Hz utility power is not made in this data extension since the possible application of where that distinction would need to be made is incredibly small. For the very few applications where mains frequency would be of any concern to other users, APRS nodes may otherwise include a note on the power frequency. One possible method would be <code style="box-sizing:border-box;font-family:consolas,"liberation mono",menlo,courier,monospace;font-size:13.6px;padding:0.2em 0px;margin:0px;background-color:rgba(0,0,0,0.0392157);border-radius:3px">PWR=U(50Hz)</code>; power capability parsers should terminate at the '(' and need not process the frequency indication after it.</p><div><div class="gmail_signature"><br></div><div class="gmail_signature"><br></div><div class="gmail_signature"><br></div><div class="gmail_signature"><br></div><div class="gmail_signature">--<br>Kenneth Finnegan, W6KWF<br><a href="http://blog.thelifeofkenneth.com/" target="_blank">http://blog.thelifeofkenneth.com/</a></div></div>
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