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:

Send Frame Tool

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:

Send Frame Tool

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

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:

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.