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 https://www.student.cs.uwaterloo.ca/~cs452/ .

Normal procedures

Trains

• 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

Track

• 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

Trains

• 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.

Track

• 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