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Setup Measure Velocity Track


  • Setup


Menu → Tables → MVTrack… open this dialog to activate a Velocity measuring on a track:

By default, the measured values are displayed as tracees in the server window, see Result view on this page.

  • Note: Trace level Calculation of the server must be activated.

To set the results in a text field of the track plan, see Actions on this page.

See also:

Distance / DistanceR

Distance between sensor 1 and 2 respectively sensor 2 and 1 (DistanceR) in mm respectively cm according to the setting in the Plan properties
If the option One-way is set, the right field DistanceR is deactivated.

See also How to define the distance

Convert to MPH

The measured value is displayed in 'miles per hour'.


If this option is deactivated the MVTrack can be used in both directions.
:!: This option can only be used if the underlying sensor system generates only one event for a train. (Delayed off.)
If the reverse direction distance is not equal to the forward direction the second distance field can be used for the reverse distance. If left zero the first distance field will be used for both directions.


A file with the name "mvtrack.csv" is created in the server working directory with the following content:


Remark: Unless the LocoID will not be forwarded by BiDi systems dynamically, "LocoID" = "unknown" is inserted (as well as "TrainID"). Example:


Shall the LocoID be displayed without use of BiDi systems, measure velocity track in the block must be utilized.

An import in a spread sheet could looks like this:


If activated the selected loco will get informed of the measured kmh and will adjust its CV 5 value to match the wanted Max. km/h.
Multiple runs at the highest speed step are necessary to come close to the wanted result.
Depending on the hight of the difference between Vtarget and Vactual, CV5 will be varried.
If the used sensors will report a loco Code this will overwrite the selected loco ID in this dialog. (RailCom, RFID, …)

Note 1: The CV 5 will be adjusted by a POM write command.
Note 2: The CV 6 will be set by POM to 30% of the CV 5 value. (This percentage can be adjusted on the Loco Calibrate Tab.)

See also: Loco Calibrate

Calculate train length

If activated, the train length is calculated from the determined speed and the time duration for which the first sensor is active.
The result of calculation will be displayed in a additional trace line.
The trace output of the train length is independent of the setted metric units ever in mm.

  • Note: The calculation can only be done correctly if
    1. the first sensor remains activated during the entire passage of the train without interruption
    2. the train passes through the entire measuring section with a constant speed

Take measured value as loco length

If a loco is selected, the measured value will be automatically set in the Lok properties as Length.
If necessary, the measured value is corrected here according to the Plan properties.

  • Note: If the option "Calculate train length" is activated the Option "Calibrate" should be deactivated.
Important NOTE :!:
The function Take measured value as loco length - active when a loco is selected -
should only be used, if the train length is defined exclusively via the loco property Length.

If a loco is assigned to an Rocrail defined train the Loco length defined as Train length
AND the Train length calculated from the lengths of the wagons will be added.

With this of course too large calculated Train length
the automatic may not find a suitable destination for the train.

Sensor 1 / Sensor 2

IDs of the Sensor at the start (1) and at the end (2) of the MVTrack.

  • Note: At the same time, the sensors can also be used in a block, as both block and MVTrack receive the events.


Selection of an Loco ID for the option Calibrate and if at the option Calculate train length the function Take measured value as loco length may be activated.


The measured values can be used with the rocrail variables %mvspeed% and %mvtrainlen% as Dynamic text in a Action of type "text".
The action must be called with status "in" in the action control of "MVTrack".
The example assumes that the text field txtSpeed is defined.

Text action "measure"Action control of the MVTrack
calling the action "measure"

Using existing blocks

This feature, without "Calibrate" and "Calculate train length", is also available in Blocks.
The measure value is than transfer in the rocrail variable %bkmvspeed% to the block action control.

Result view

  • Note: Trace level Calculation must be activated in the server.
The average velocity and train length are shown in the Rocview server window:
Output of the lines with the train length informations only if option Calculate train length is activated.

In case of MPH the calculated KM/H is multiplied by 0.621371192.

How to define the distance

In case of current sensors measure the distance between the start of s1 and the start of s2 in mm.

:!: The measured results dependents of the used sensor system and of the data traffic.


The reset will re-initialise the MVTrack to be able to start all over again.

mvtrack-setup-en.txt · Last modified: 2023/10/19 14:00 by rjversluis