At A Glance

1
NASAs GMSEC VCR Summary The GMSEC VCR is a
Windows-based tool for recording and playing back
published messages (both publish and request) on
the GMSEC message bus. The GMSEC VCR monitors
GMSEC message bus traffic and has the ability to
save messages to an XML log file. The VCR can in
turn read this xml log file to play the messages
back through the message bus. The VCR sends
messages as they are received so it can spoof
being the original sending component. This tool
is useful for debugging purposes as well as
creating message macros and simulations.
At A Glance The GMSEC VCR is a Windows-based tool
for recording and playing back published messages
on the GMSEC message bus.

• Features
• Records all published GMSEC Messages on the bus
  to disk. Recorded sessions may be played back to
  the message bus from within the VCR or GMSEC
  Symphony playlist
• Can play back all GMSEC components messages or
  only a subset of GMSEC components
• Can Start, Stop, Pause, Step Forward, Step
  Backward, and Jump around in GMSEC VCR File
• Provides an Editor for adding, editing, and
  deleting messages

Message BusMiddleware

• Benefits
• Easy to install and use
• Easy recording and playing back of messages on
  GMSEC message bus
• Extremely helpful in debugging and simulations
• Can act as a simulator

GMSEC VCR User Interface
Implementation The GMSEC VCR is a Microsoft
Windows application, built using the Delphi
wrapper of the GMSEC API. It divides the VCR
file into separate messages for each GMSEC
Component, using the GMSEC-standard "Node" and
"Component" fields to identify a component. Each
GMSEC Component is one horizontal bar chart in
the GMSEC VCR, where time is on the horizontal
axis. Each bar at a particular time reflects at
least one message that was recorded at that time.
If more than one message was recorded at that
time, the bar is higher. The VCR allow users to
turn off GMSEC Components messages being played
back (or saved as a subset) by checking or
unchecking the pane that contains that
components bar chart.
NASA GSFC Mission Services Evolution Center, Code
581 Greenbelt, Maryland 20771 http//gmsec.gsfc.n
asa.gov email gmsec_at_nasa.gov