Querying Stations

There are several types of queries one APRS station can make to another. The most common, requesting an updated position report, is automatically issued on a Locate->Station request if YAAC doesn't have recent position information about the requested station. Other common queries include:

In addition, YAAC can make broadcast queries to search for RF-local stations, either any APRS station, or those performing I-gate or weather station functions. These broadcast queries can only be used when YAAC has a RF connection.

Also, YAAC can broadcast QRU requests to find out about local resources of various types. Some of the standard QRU groups that are commonly used are:

group namemeaning
AMBUambulance
CLUBham radio club
ECHOEcholink
FIREfire station
FOODrestaurants
FUELgas/petrol stations
HOSPhospitals
LIFEBOATlifeboats
LTHSlighthouses
POLIpolice stations
POSTpost offices
RD13D-Star 13cm repeaters
RD23D-Star 23cm repeaters
RD2MD-Star 2m repeaters
RD3CD-Star 3cm repeaters
RD70D-Star 70cm repeaters
RP10analog 10m repeaters
RP13analog 13cm repeaters
RP23analog 23cm repeaters
RP2Manalog 2m repeaters
RP3Canalog 3cm repeaters
RP6Manalog 6m repeaters
RP70analog 70cm repeaters
RT13television 13cm repeaters
RT23television 23cm repeaters
RT3Ctelevision 3cm repeaters
SRAILsteam railroad
STORAmateur Radio stores
T2SRVapproximate locations of Tier 2 APRS-IS servers
VETEveterinarians
WOTAWainwrights On The Air peaks

To find out what QRU codes are in use in your area, send the default query INFO; every QRU server station in range will report the QRU codes they serve and their maximum range.

YAAC can also send and receive lists of tactical callsigns (aliases) in use by RF-local stations and objects; this message interchange is compatible with Xastir and APRS+SA.

The APRS-standard and custom queries that YAAC will respond to are:

Directed query codeResponse
??This list of query commands recognized by YAAC.
?ABOUTThe version of YAAC software being used.
?ALOHAThe current radius of the Aloha circle for this YAAC station.
?APRSDThe list of directly heard stations.
?APRSH callsignThe number of messages heard from the specified station for each of the last 8 hours.
?APRSLThe list of stations considered local for I-Gating by this station.
?APRSMImmediately retransmit all unacknowledged messages transmitted to the requesting station.
?APRSOImmediately transmit all objects and items controlled by this station.
?APRSPImmediately transmit the current position of this station.
?APRSSImmediately transmit the current status message of this station.
?APRSTA message with the path from the requesting station to the queried station.
?APRSVThe version of YAAC software being used.
?IGATEIf this station is functioning as an I-Gate, the I-Gate statistics for this station.
?PING?A message with the path from the requesting station to the queried station.
?QUERIESThis list of query commands recognized by YAAC.
?UPImmediately transmit the duration of time this instance of YAAC has been running.
?VERThe version of software being used.
?WXIf this station has a weather station attached, immediately send the station position and a positionless weather message.
?YDBGReport debugging information about the local YAAC station, including memory consumption, station/object quantity being monitored, current map pan and zoom, and thread status.
Broadcast query codeResponse
?APRS?Immediately transmit the current position of this station.
?IGATE?If this station is functioning as an I-Gate, the I-Gate statistics for this station.
?WX?If this station has a weather station attached, immediately send the station position and a positionless weather message.
Broadcast message destinationMeaning
QRUask for local resources
TACTICALsend or receive tactical callsign aliases for real callsign-SSIDs