Real-Time Lab Administrator Procedures

General information

  • The Real-Time Programming Lab (aka the Train Lab) is in MC 3018.
  • Spare parts and specialized tools are stored in DC 2561 in the Teaching and Administration shelves.
  • The course home page is .

Normal procedures


  • purchase
    • record (at least) Marklin part number and date purchased
  • prep
    • record (at least) address, Marklin part number (and preferably) date put into service
    • set address
    • remove couplers
    • remove parts that normally break or fall off
      • especially pantographs
  • lube and tune-up after 40 hours of operation
    • lube per manual, typically:
      • oil axles
      • grease worm gear or oil motor bearing and gears
    • clean pickup and wheels
    • replace missing tires. Some trains have none, some have 2 or some other number. Look for a wheel with a ridge to retain the tire.
    • check for damaged parts
    • check body retaining screw(s) are adequately tight
    • test:
      • motor runs smoothly at a variety of speeds in forward and reverse
      • quick large changes in requested speed result in gradual acceleration or deceleration
      • all lights work and do not flicker excessively while moving
      • (some models) horn works
      • train does not derail when passing through turnouts


  • periodic tune-up (at least once per term)
    • remove debris
      • it is OK and normal for the small turn-out manual operation levers to be not installed in the turnouts and scattered about the track table
      • it is common to find small parts of trains broken or fallen-off scattered about the track table. Usually they are not worth keeping, but sometimes they are.
    • clean tracks and third rail with rubbing alcohol
    • check turn-outs for broken guide rails
    • look for damage

Common repairs


  • for most problems, start with 40 hour tuneup
  • all functions (lights, motor, etc.) do not respond to commands
    • clean pick-up
    • check for broken red wire from pickup to pcb
    • check for broken ground wires from trucks to pcb
    • if it has mfx, does it register itself within 30 seconds on the test track?
    • check for overheating (internal short) ICs
  • motor does not respond to commands, but lights, etc. work
    • check drive train moves freely
    • check for broken wires to motor (some models)
    • check for overheating (internal short) ICs, especially motor drive fet
  • missing tire
    • train may sometimes derail or short track
    • replace tire
  • bent pickup
    • should project (2mm?) (per manual) beyond wheels and be parallel to track
    • remove (pops off with small flat-head screwdriver) then straighten or bend into shape, or replace
  • frequently stalls, lights flicker
    • clean pickup and wheels
    • check for bent pickup
  • sounds rough, runs slowly or erratically
    • lube per 40 hour tuneup
    • check drive-train for smooth operation
    • (some models) check for disconnected or missing drive shaft(s)
    • (some models) remove drive shafts and check motor
  • motor responds to commands, but some or all drive wheels don't turn
    • (some models) check for disconnected or missing drive shaft(s)
  • (some models) wheel axles loose or falling off
    • re-assemble truck
      • bronze ground brushes go inside wheels
      • plastic bottom trim snaps into place on truck and retains both axles
      • drive shaft connects motor to worm gear in truck
  • train derails on turnouts
    • check turnout for broken guide rails, other damage, missing parts, or incorrect operation
    • check for bent pickup or missing tires
    • train may derail only when travelling backwards and in direction that turnout diverges
    • check for loose press-fit of wheels on axle. Wheels a fraction of a millimeter too far apart will cause this problem.


  • turnouts
    • trains derail on turnout
      • check for broken guide rails
      • check for damaged or missing moving rails
      • check for moving rails not fully in position for straight or curved
      • check for correct operation
        • smooth manual operation from straight to curved and back
    • does not respond to commands
      • replace track if necessary
        • check for smooth manual operation from straight to curved and back
        • look for broken parts
        • move solenoid and decoder to new track
      • else, replace solenoid. A solenoid will burn-out if left energized more than briefly by the program.
      • else, check turnout decoder pcb address dip switches; look-up in manual that comes with every new decoder.
      • else, replace decoder pcb. Set address dip switches to match old decoder.

  • sensors
    • does not trigger in one or both directions, or
    • can be triggered by hand, but not trains, or
    • stays triggered in one or both directions, or
    • triggers in one direction, then bounces and triggers opposite direction
      • replace sensor track if necessary
        • check for smooth operation
        • listen for click of microswitches
      • check for broken wires under track
      • check for plugs disconnected or misconnected to 16-input encoders under track
    • directions are reversed or the wrong sensor reports trigger
      • check for wires reversed to sensor track
      • check for plugs misconnected to 16-input encoders under track

Computing equipment

thin client problems

  • ask Clayton or Anthony

TS-7200 ARM (small grey boxes)

  • check for loose ethernet cable
  • check PC is connected to COM2, track (if present) connected to COM1, nothing connected to COM3
  • check correct baud rate and TTY on PC
  • check status LEDs on pcb inside
  • check jumpers per manual
    • console on COM2, because track interface need RS232 modem control signals on COM1
    • flash write disabled
  • check ribbon cables
    • COM1, COM2 OK; COM3 disconnected
  • if Redboot in flash is damaged
    • reprogram flash using reprogramming board, or return to Technologic Systems for reprogramming.

track PC

  • stock Ubuntu Desktop install, with
    • user realfolk
    • login automatically
    • disable screen lock
    • install gtkterm
    • see other notes

tftp servers

  • tftp1.student.cs and tftp.student.cs
  • Ubuntu LXC containers
  • minimal installed software
  • students in the course have group write perms on student.cs file server ~cs452/tftp/ARM/ download dir
  • tftp servers nfs mount home dirs to get ~cs452/tftp/ARM/

-- FraserGunn - 2015-07-16

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Topic revision: r3 - 2016-02-23 - FraserGunn
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