Bachrus Speedometer

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Set up the loco to be measured on a running stand with the reader unit appropriate to the track gauge, connected to the MTS-DCC which is connected, in turn, to the PC.

Connect the track on which the running stand is installed to your DCC system.

Add both the DCC system and the reader interface as layout connections in the JMRI preferences. Open the Speedo console from the Speedo menu on the main screen of DecoderPro or PanelPro.

The left side of the window is used for setup and to display the current speed:

Select Scale: The reader type will be detected when the loco is driven and speed data is received from the reader. Use the Scale drop-down to select the appropriate locomotive scale in order to get the correct speed values.

Select Mode: If you have a DCC system that can run locomotives on the programming track (such as the SPROG) then select "Run profile on programming track" as this will allow reading the locomotive address, etc. without moving between the programming track and a running track. If you can't run locomotives on your programming track, then select "Run profile on the main track".

Measured Speed: The radio buttons to the right of the dial allow the primary (black) speed digits to display the scale speed in either Miles-per-Hour (MPH) or Kilometers-per-Hour (KPH) units. The secondary (green) digits display will show the other units. The speed is displayed digitally in the primary units in the small window at the bottom of the dial. The units on the speed profile graph also change to match. If the measured speed exceeds the maximum value on the dial, it will automatically re-scale itself to match. This can be reset using the "Reset Graph" button under the speed profile chart.

Selecting the Numeric radio button will change the dial to just a box with the speed numerically displayed.

At this stage you can use a throttle (either part of your DCC hardware or a JMRI throttle) to drive the loco and observe the scale speed.

The right side of the window is used to measure the loco speed profile:

Loco Selection: There are several ways to select the locomotive to profile:

• You can enter the loco's DCC address manually by entering it in the text box, selecting whether it is a long or short address in the drop-down, and pressing the "Set Loco Address" button.
• If the loco is already in your roster, you can select it from the roster drop-down and its address will be selected automatically.
• If the DCC hardware supports service mode programming and you have selected "Run profile on programming track" in the "Select Mode" section, you can press the "Read" button to read the address directly from the loco.

Speed Profile Chart: The radio buttons to the right of the chart allow you to select whether you want a profile for the locomotive running forward, or backwards, or both. The grid lines on the chart can be toggled off and on as well.

Underneath the chart area are several buttons that control the creation of a speed profile:

• Power Up/Power Down: This button allows you to manually turn track power on or off. It is also automatically invoked when a speed profile run is invoked.
• Start: This will start the running of a speed profile based on the other settings on the screen.
• Stop: This can be used to stop a profile run before it is finished. When a profile is finished the locomotive is automatically stopped and the track power is turned off.
• Export: This will allow you to export the results of the speed profile to a comma separated variables (CSV) file. This is a plain text file that can be opened by many other programs, including spreadsheets.
• Print: Use this to print a copy of the speed profile chart
• Reset Graph: This button will reset both the speed profile chart and speedometer dial scales to their default values if they have done an automatic re-scale because the speeds exceeded their limits. It also will erase any speed profiles being displayed.
• Load Ref: This button allows you to import a prior speed profile as a reference to make it easier to do speed matching. The profile can be one from another locomotive, or one that you create yourself with your desired speed values. The file to be loaded needs to match the format used for the Export function - there must be no less than 31 lines in the file with the following format:
  • First line is a text header than can be any text.
  • Second line holds the column headers - the main requirement is that the units used in the profile appear as "MPH" or "KPH" somewhere on the line. This is used for appropriate unit conversions when the profile is loaded.
  • The next 29 lines hold the speed information, one line per speed step. The line must have the speed step number followed by a comma, and then the value for the speed. There can be more speed values on the line (for example if the file is an export of a forward/reverse speed profile) but the rest of the line is ignored. Note that the speed step number isn't actually used - the loading function simply assigns the 29 speed values in sequence, but something must be there since the second value on the line is used as the speed value.
  • The easiest way to create an appropriate file is to Export a profile and then modify the speed values in the exported file (if needed).

For best results the momentum CVs should be set to zero so that speed commands take immediate effect.

Speed Matching: At the bottom of the right side is a "Speed Matching" section. This configures the Vstart (3) and Vhigh (4) CVs to match the your desired speeds at speed step 1 and 28. The Vmid CV is set to half way between these to attempt to set a straight-line speed curve.

Note that after these CVs have been set by running the matching, you should go to the DecoderPro roster entry for this decoder and do a "Read Full Sheet" of the "Basic Speed Control" pane to capture the new values.

If you are doing this on the the programming track, the process will have set the momentum CVs to zero and restored them on successful completion. This is done to avoid them interfering with the matching process. If you're programming on the main track, this step is skipped. In that case, make sure that you have set the momentum CVs to zero before starting the process, and restore them manually afterwards.

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