Select files have many parts. The basic part of a select file is called a chain. Most select files only have one chain. A single chain contains descriptions of what network/station/location/channel/date-time groupings that are to be considered interesting for selection.
Multiple chains can combined together to make multiple requests in one select file.
Individual chains can be tagged. These tags permit the user to label individual requests. These tags can then be presented back to the user (by software that supports this feature) along with actual data, permitting the user to make very complex requests and build post-processing programs that understand and exploit the nature of the original requests.
The station selector adds (+) or removes (-) stations from the list of stations to be considered for selection. Network and station codes may include wildcards. If the +/- codes are omitted, they will default to add (+). Multiple network/station lines can be present to specify a complex set of stations.
This creates two sets of stations (possibily with wildcards): the add-set and the subtract-set. Data selected will be the set specified by the union of the all network/stations in the add-set, with the union of all of the network/stations in the subtract-set subtracted. This resultant set is called the station-set.
This channel selector adds (+) or removes (-) stations from the list of stations to be considered for selection. Location and channel codes may include wildcards. If the +/- codes are omitted, they will default to add (+).
This creates two sets of channels (possibily with wildcards): the add-set and the subtract-set. Data selected will be the set specified by the union of the all location/channels in the add-set, with the union of all of the location/channels in the subtract-set subtracted. This resultant set is called the channel-set.
This selector adds date ranges into the selection sets. DCC date formats are of the following form: MMMM,JJJ,HH:MM:SS.MMM, where MMMM is the year (with century), JJJ is the Day-of-the-Year (Jan 1 = 1), HH is the hour (0-23), MM is minutes (0-59), SS is seconds (0-59), and MMM is the fractional milliseconds (0-999). The date can be truncated at any punctuation mark after the date.
The union of all of the dates selectors specified result in the date-set. If no dates are selected, the date-set set defaults to all.
STATION=+IU/*
STATION=-IU/ANMO
CHANNEL=+*/L*
DATE=1994,1/1995,1
TAG=MAIN
//
All of the data from ANMO (no TAGs):
STATION=+IU/ANMO
CHANNEL=+*/*
//
A complex multi-chain query involving multiple events and windows.
STATION=+IU/ANMO
CHANNEL=+*/LH*
DATE=1997,200,20:00/1997,201,12:00
TAG=EVENT1_ANMO_LH
/
STATION=+IU/ANMO
CHANNEL=+*/B*
DATE=1997,201,05:00/1997,201,06:00
TAG=EVENT1_ANMO_BH
/
STATION=+IU/KIP
CHANNEL=+*/LH*
DATE=1997,200,20:00/1997,201,12:00
TAG=EVENT1_KIP_LH
/
STATION=+IU/KIP
CHANNEL=+*/B*
DATE=1997,201,05:30/1997,201,06:30
TAG=EVENT1_KIP_BH
//