wiki:export_scn
Last modified 9 years ago Last modified on 05/02/12 09:27:10

Earthworm Module: export_scn

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Function

Exports EARTHWORM messages over Internet (partner to import_generic).

Details

Import-Export Overview

EXAMPLE CONFIGURATION FILE

#  export_scn configuration file
#
#  Exports messages from a given list of station/channel/network codes
#  Knows how to decipher TYPE_TRACEBUF, TYPE_PICK2K, TYPE_CODA2K msgs
#
#Background:
# Import/Export are the long-distance message transfer
# modules. They operate as one-on-one pairs. There are two variants of
# export: export_generic, which ships messages with specified logos, and
# export_scn which ships only trace data, but with specified SCN names.
#
# Import/Export send heartbeats to each other, as well as into their
# local earthworm systems. If the heartbeat from the distant partner is
# not received whithin the expected time period (RcvAliveInt) the link is
# terminated, and an attempt to reconnect is initiated. If things go
# seriously wrong, the heartbeat into the local earthworm system in
# stopped. The expectation is that "restartMe" has been set in the .desc
# file, and we'll be killed and restarted.
#
# All socket operations are performed with a timeout. This is noramlly
# defaulted, but can be set in this file (SocketTimeout).
#
# Export maintains a circular FIFO buffer of messages to be shipped. The
# size of this buffer (RingSize) controls the maximum latency of the
# data.
#
#
#Configuration notes:
#
# "restartMe" should be stated in our desc file.
#
# The period of our local heartbeat (HeartBeatInt) must be safely smaller
# (faster) than our advertised period in our .desc file (tsec:).
# Otherwise we'll get continually restarted for no good reason.
# Note that tsec:0 implies no heartbeats expected, and so we'll never get
# restarted.
#
# The rate at which we send heartbeats to our distant partner should be
# considerably faster than the rate at which our partner expects them.
# Otherwise, a heartbeat delayed in transmission will cause our partner to
# conclude that the link is broken, and cause them to break the link and
# reinitialize. Which will cause us to do the same.
#
# For export, the ServerIPAdr is  the address of the port to be used in
# the exporting machine.  This is to specify a network card case the
# exporting machine has several network cards.
#
# If SocketTimeout is specified, it should be at least as large as the
# expected period of heartbeats from our distant partner.
#
 MyModuleId     MOD_EXPORT_SCN      # module id for this program
 RingName       WAVE_RING           # transport ring to use for input/output
 HeartBeatInt   30                  # EW internal heartbeat interval (sec)
                                    #   Should be >= RcvAliveInt
 LogFile        1                   # If 0, don't write logfile; if 1, do.
                                    # if 2, write to module log but not to
                                    # stderr/stdout

#
# Logos of messages to export to client systems
#              Installation       Module       Message Type
 GetMsgLogo    INST_MENLO      MOD_WILDCARD     TYPE_TRACEBUF

# ServerIPAdr and ServerPort specify the local IP address and port number
# on which this module will be ready to accept a client connection.
#
 ServerIPAdr  aaa.bbb.cc.ddd   # Export messages via this ethernet card
 ServerPort     16005          # Well-known port number to export msgs on

 MaxMsgSize       900          # maximum size (bytes) for input/output msgs
 RingSize	  100	       # max# messages in outgoing circular msg buffer

 SendAliveText   "alive"       # string sent to client as heartbeat
 SendAliveInt      30          # seconds between alive msgs sent to client.
                               #  0=> no heartbeat
 RcvAliveText    "alive"       # text of client's heartbeat (we get this)
 RcvAliveInt       150         # seconds between client's heartbeats to us.
                               #  0 => no heartbeat

#MaxLatency        0           # Optional command; Packets with delay time
                               #  (i.e., time between present and packet
                               #  start time) greater than this amount will be
                               #  filtered out.  Time is in minutes.  0 -> time
                               #  is not checked.  System time must be accurate.
                               #  Only works on TYPE_TRACEBUF messages.

# Socket commands
# The commands below are optional.
# SocketTimeout defaults to RcvAliveInt + 3
#  If set to -1, all socket calls will block (no timeout).
#  SocketTimeout has no effect in export, unless it is set to -1,
#  because there is no code in export to handle socket timeouts.
#  If set to -1, the program may run slightly more efficiently because
#  timeout checking code will not execute.
#
 SocketTimeout 200000  # Timeout length in milliseconds for socket calls
                       # this should be atleast the value of the RcvAliveInt
 SocketDebug   0       # if 1, socket_ew debug statements are logged
                       # if 0, socket_ew debug is turned off

# List of station/channel/network codes to export.
# Use any combination of Send_scn (to send data as-is)
# and Send_scn_remap (to change the SCN on the fly) commands.
# Use * as a wildcard for any field. A wildcard in the
# "map to" fields of Send_scn_remap means that field will
# not be renamed.
#
#               send SCN     map to SCN
Send_scn        JMP ASZ NC               # send this specific channel
Send_scn        JPS *   NC               # send all components of JPS NC
Send_scn_remap  JGR VHZ NC   *   EHZ *   # change component code only
Send_scn_remap  CAL *   NC   ALM *   *   # send all component of CAL, but
                                         # change the site code to ALM

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