Monitoring:

• tiedown tensions
• daily check of positions, commands, motor torques.

Failure and modifications log

hardware:

• tiedown huffman box Schematics
• Hagens tiedown memos
• Load cells
• Load cell locations, history,
• Load cell calibration
  
• Load cell resistances measured at input to amp (used to see if db25 connector has blow filter)
• load cell amplifiers
• fiber optic tx,rx
• Motors
• motor/amp specs
• motor personality modules
• Limit switch positions/encoder reference
• 28feb10.. looks like above link was overwritten by the failure log 09aug18.
• I went and grabbed some really old info (around 2012 from megs2.old..
  

• Grounding the tiedowns.
• Possible replacement hardware for little star based system:

Software

• Little star software
• Description of AtoD signals. 
• Tiedown power supply startup sequence.
• Little star communications protocol (draft) (.pdf)

Misc:

• Misc. notes on things.
• Switching to kevlar cables for the tiedowns.
• Tiedown reference position used to point the telescope
• Pictures of tiedown system
  

Debugging

Description of specific events

Hardware:

Schematics:

Hagen's tiedown  memos:

• BSD4 amplifier (.pdf)  : description of  Kollmorgan amplifier.
  
• kolmorgan (.pdf) : testing a kollmorgan 606 amplifier to replace the old tiedown motors.
  
• lightniing (.pdf)  Lightning protection references.
  
• loadcells (.pdf)  load cell calibration
  
• motor1 (.pdf)  Brushless DC motor servo motor operation.
  
• motor2 (.pdf)  Brushless DC motor servo motor operation.
• motor3 (.pdf)  Switching converter for motor control.
  
• motor4 (.pdf)   Switching converter for motor control.
• torque. (.pdf)   Motor torque required to lift tiedown block.

Fiber optic xmter/rcvr for 1 second tick

• xmiter (min,typ,max) -20,-160,-14 dbm 62.5/125 um fiber
• page 14
  
• rcvr: (2412 page 19)
  
• Logic High : -40 dbm max
• Logic low   : -25.4 dbm min, -9.2 dbm max 100/140 um fiber (page)
• Optical power levels.1 sec tick  measured 25feb12 using 3 separate fibers driving ticks
• Prior to 25feb12 the 1 sec tick was sent down on a single fiber to box 12-7. It was then split  and sent to the individual tiedowns. The splitter was lossy (about 13 db). The  1 sec tick rcvr were receiving power levels near -25dbm. This was lower than the required power level (-24dbm) for the FO rcvr chip.
• On 25feb12 a fiber optic buffer was installed in the back of the pnt vme crate. It takes a single fiber input and generates 3 separate fiber outputs. These are then sent to tiedowns 12,4,8 on separate fibers (so the splitter is no longer needed). The table below shows the optical power levels measured on 25feb12 after the new 1 sec tick fibers were installed.
  

• Optical power levels for  1 sec ticks using separate fibers (25feb12).

  	td12	td 4	td8
  power @box b1 cable 5 in control room
  power @ box 12-7 before patch to each huffman box (n) is fiber number in 12-7	-17.8 (3)	-17.3 (5)	-18.5 (4)
  power @ 1 sec tick rcvr	-18.6	-18.1	-19.8

Motor personality cards

• td12 (.jpg)
• td04 (.jpg)
• td08 (.jpg)
  

Software

Little star Software:

• Third party documentation:
  
• Pk2200 users manual (newer little stars) (.pdf)
• Dynamic C 32 technical reference (from rabbit.com) (.pdf)
• Dynamic C Applications framework (.pdf)
  
• Dynamic C function reference (.pdf)
• changes to serial eeprom boards.
  
• Z180 user manual (.pdf)
• Our documenation:
  
• Interrupt usage
• How the little star timing works (1 sec tick,  control law,,...)
• Versions of the little star software on maestro.

Tiedown power supply startup sequence:   (top)

1. the safety is closed.
2. the master contactor is closed.
3. there are no power supply faults.
4. you have requested the tiedowns to move.

1. POWER1 to energize the master contactor relay to startup
2. POWER2 to drive the master contactor relay during normal operation inline with the power supply fault contactor and the safety.

1. reset will close the safety if there are no safety problems (eg.blk liftoff, emg stop, etc.).
2. You must command the tiedowns to move (it can be to the current position) or use the pcu to turn the drives on.
3. The little star will driver 24 volts through POWER1  dio2 pin 2,3 for about 300 milliseconds. This provides power to the master contacter relay PS_MC_R if the saftey is closed.
4. PS_MC_R closes the master contactor and the 3 phase power is supplied to the power supply. The power supply will then close the power supply fault contactor (PSR_4_FAULT* goes high). 24 volts is wired through the power supply fault contactor, throught the POWER2 contactor in the little star, the safety, and then the PS_MC_R.
5. The little star loops up to 20 times checking to see if PSR4_FAULT* goes high (about 100ms/loop i think). This is pin DIO1 J3 pin4 --> lsPin03.  If after 20 times through the loop the contactor hasn't closed, then the little star will drive POWER1 to 0, open POWER2 and log fault 12 (PSR_FAULT psr4F).

Tiedown reference position:

 Pictures of tiedown system:

• td 8 jack
  
• td 12:
• td limit switches
• Bar to set encoder value (looking down from top)
• Bar to set encoder value (looking at bottom).
• transmission, jack coupling 
• transmission, jack separated
  
• td 12 boom,mast from td4 corner of triangle
• td 12 boom, backstay cables from center of triangle
• td 12? top of mast
• td backstay connection point at  u2-u2l3
• Td cable grounding connections:
• td 8 looking at yoke from block
  
• ground to cable connection(entire clamp)
  
•  ground to cable connection(bottom of clamp)
  
• ground to cable connection (top of clamp)
  
• grounding cable size (that's dana's hand..)
  
• laying Grounding
• Jorge covering grounding trench at td12
• Jorge and eddie (1) at td12
• Jorge and eddie (2) at td12
  
• luis At td 12
  

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debugging:

• If td does not stop when you send stop command, or off.. the it is probably being controlled by the watchdog timer.
• If the velocity feedback sits at a constant negative value (about -300) then this is probably the watchdog timer circuitry driving it.. the amp speed monitor should be around -400 counts.
  

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