Playback Type Function Block

The Playback function block will transmit a previously collected Vehicle Spy buffer according to the timestamps recorded.  To setup this type of function block, simply select a data file and how many times you want it transmitted.  You can transmit a specific number of times or continuously.

A common application is to collect network traffic and then play it back to test a particular electronics module.  This is illustrated in the following example scenario.

An Example Scenario

  1. A problem was found with the cluster on a durability vehicle.
  2. Vehicle Spy is used to collect all the data on the network in the vehicle.
  3. In the lab, Vehicle Spy is set up with a Playback function block and used to play back the collected data to the cluster on a test bench.
  4. The vehicle problem is replicated on the bench.
To setup which data file to use, click browse and select the desired file .  Replay data files can be made by hand or can come from Vehicle Spy *.CSV log files.  A *.CSV log file can easily be made with a text editor or a spreadsheet program such as Microsoft Excel.  If you create your own data file, you must have the text "Line," to identify the first row of data in the file.  The following is valid data as it would be seen in Notepad.  If you create a bad data file, Vehicle Spy will tell you when it loads the file.

Line, Time(Sec), Status, Err/CC, PT, Trgt, Src, B1,B2,B3,B4,B5, B6, B7, B8, Trigger
1,0.216,67108896,FALSE,28,93,C0,1,9F,AF,,,,,,
2,0.221,67108896,FALSE,68,33,28,A2,,,,,,,,
3,0.225,67108896,FALSE,49,92,C0,42,,,,,,,,
4,0.23,67108896,FALSE,68,85,28,3,AA,,,,,,,
5,0.236,67108896,FALSE,68,EA,10,A,1,,,,,,,
6,0.241,67108896,FALSE,88,25,28,3,0,,,,,,,
7,0.247,67108896,FALSE,68,97,80,11,9D,0,,,,,,

Setting up the number of iterations is done in the "How many generations" section of the dialog .  The Continuous option means that Vehicle Spy will transmit the buffer until the function block is stopped.  The "A Number of Generations" option lets the user select the number of iterations to run before the function block stops.

Note: You can modify and manipulate your data file in Excel to change the timing of the replay.  This would be useful if you only wanted to find one particular message that was causing issues.  You could slow it down to say one message per second, and then you can watch and see what message caused an issue.


Figure 1: Collect message traffic and replay it on the bus with the "Playback" Function block.

  Vehicle Spy Documentation - (C) Copyright 1997-2011 Intrepid Control Systems, Inc.

Last Update: Monday, August 23, 2010