pkfilter is a pick filtering module designed to prevent duplicate picks. Below is a copy of the .d file with detailed notes on each parameter
# pkfilter configuration file
# Basic Earthworm setup:
#------------------------
MyModuleId MOD_PKFILTER # module id for this instance of pkfilter
InRing PICK_RING # shared memory ring for input
OutRing FILTERPICK_RING # shared memory ring for output
HeartbeatInt 30 # seconds between heartbeats
LogFile 1 # 0 log to stderr/stdout only
# 1 log to stderr/stdout and to disk file
# 2 log to disk file only
Debug 1
# List the message logos to grab from InRing, WILDCARDs permitted.
# Multiple "GetLogo" commands are allowed, with no hardcoded limit.
# Installation Module Message Types
#-----------------------------------------------------------------
GetLogo INST_WILDCARD MOD_WILDCARD # TYPE_PICK_SCNL & TYPE_CODA_SCNL
# TYPE_PICK2K & TYPE_CODA2K
# Pick Filtering Parameters
#--------------------------
PickHistory 5 # Keep track of this many picks which have
# made it thru the filter for each station.
PickTolerance 3.0 # If pick times are within this many seconds of
# each other, they are "duplicates."
OlderPickAllowed 1 # 0=reject any non-duplicate pick whose
# timestamp is earlier than the youngest
# passed pick for this station.
# 1=accept a non-duplicate pick whose timestamp
# is earlier than the youngest passed pick,
# but place a limit on how old it can be.
# Must also use the "OlderPickLimit" command.
# 2=accept any non-duplicate pick whose
# timestamp is earlier than the youngest
# passed pick.
OlderPickLimit 30 # Required only if OlderPickAllowed = 1
# Accept an pick whose timestamp is between
# PickTolerance and OlderPickLimit sec
# earlier than the youngest passed pick
# from this station.
DuplicateOnQuality 1 # If non-zero, transfer a duplicate when its
# quality is better than the original.
QualDiffAllowed 1 # Required quality difference for later pick to
# be allowed to pass as a duplicate.
# 0 means any pick greater than current pick
# 1 means a pick of 1 replaces a pick of 3
# 2 means a pick of 0 replaces a pick of 3
# 3 is invalid because it is equivalent to
# turning off the duplicate on quality test
# List of Allowed Components
#---------------------------
# If you want ALL component codes to be eligible to pass thru
# pkfilter, comment out all "AllowComponent" commands.
# If you want to limit which component codes pass thru pkfilter,
# use one "AllowComponent" command for each allowed component code.
# A component refers to the CHANNEL name in the SCNL tuple.
AllowComponent VDZ
AllowComponent VHZ
AllowComponent VLZ
AllowComponent SHZ
AllowComponent SLZ
AllowComponent EHZ
AllowComponent HHZ
AllowComponent BHZ
AllowComponent DP1
AllowComponent DP2
AllowComponent DP3
AllowComponent EP1
AllowComponent EP2
AllowComponent EP3
# Coda Filtering Parameters
#--------------------------
CodaFilter 1 # Possible coda filtering values:
# 0 = allow no codas thru filter
# 1 = allow only codas which match passed
# picks to pass thru filter
# 2 = allow all codas thru
# Optional commands:
#-------------------
MaxMessageSize 128 # length (bytes) of largest msg to be processed
# from InRing. Default=MAX_BYTES_PER_EQ
UseOriginalLogo 1 # 0 apply pkfilter's logo to any messages that
# pass the filter test (normal Earthworm behavior)
# non-zero means apply the original logo to any
# messages that pass the filter test. This
# also requires that InRing and OutRing be
# different to avoid "missed message" or
# "sequence gap" storms in pick-reading modules.