M3 Retrofit

After M3 is disassembled for mirror coating and actuator profiling, mirrors tip tilt accuators have to be adjusted.

This consist of the following steps:

Establishing a connection from the SWG group laptop to UMAC running the OSS

The Dell laptop has Windows installed, with Virtual Box image of Centos. User to Windows is swg (no password), Centos 7 username is tcs, password written on the laptop. After starting Centos (and extending the Centos screen), click on OSS icon to launch OSS GUI. Click on M3 to access M3. Configuration for OSS is specified in tcs/oss/etc/oss.conf directory, contains tertiary IP address on the following line:

oss.terc.ip                     map<int,string> 0: 1: # ip address of the M3 UMAC.

The laptop must be connected by an ethernet cable with the tertiary UMAC box.

The connection can be verified by pinging IP from the laptop terminal.

Calculating new home offset

A new home offset must be calculated. Engineering knows the procedure (includes driving encoders to limits, obtaining free of travel range, and dividing this range by 2 to get the home position in the middle of the range). After those offsets are calculated, 3 numbers corresponding to 3 legs will be provided.

Writing new home position to the OSS source code

The home offsets are recorded (hardcoded) in (tcs)/oss/TertiaryMirror.cpp file, about lines 150:

  150	// make class variables 1-Sep-16
  151	        // measured in lab 2-Sep-16
  152	        leftSelHomeOffset =  "-325520";
  153	        // measured in lab 14-Aug-17
  154	        leftLeg1HomeOffset = "-428160";
  155	        leftLeg2HomeOffset = "-478784";
  156	        leftLeg3HomeOffset = "-492816";
  158	        // measured in lab 25-Aug-15
  159	        rightSelHomeOffset =  "-436540";
  160	        // measured in lab 20-Aug-15
  161	        rightLeg1HomeOffset = "-265160";
  162	        rightLeg2HomeOffset = "-376048";
  163	        rightLeg3HomeOffset = "-292320";

After changing the limits (on aproprite side), compile and restart OSS by typing:

netconfig stop OSS
netconfig start OSS

Updating M3 software limits

UMAC firmware has to be updated to reflect newly calculated software limits on actuator travel. Those are stored in (tcs)/oss/etc/terc/umac_m3s_config_[SIDE]_source.CFG. The file must be edited, lines with assignment to software limits registers identified, and updated:

 1001	END IF
 1002	;I113=8192
 1003	;I114=-8192
 1004	;I213=8192
 1005	;I214=-8192
 1006	;I313=8192
 1007	;I314=-8192
 1008	I113=12288
 1009	I114=-12288
 1010	I213=12288
 1011	I214=-12288
 1012	I313=12288
 1013	I314=-12288

After the I values are updated (only those, the code contains seconds assignments of 0 - leave those alone, those are to disable software limits during accuators initialization), load new firmware by typing:

cd oss/etc/terc
source [SIDE]terc

Where [SIDE] should be replaced with SX or DX.

Verifying values, versioning

After you changed the values, verify that new numbers are in effect. Commit changed files (both oss/TertiaryMirror.cpp and UMAC firmware) into git current branch (as this is one time small change, directly pushing them will work - no branch needed; please keep in mind only TCS admin has direct write access, so create branch and pull request or send git diff to TCS admins if you aren't in the group).

-- PetrKubanek - 2018-07-24
Topic revision: r2 - 20 Aug 2018, PetrKubanek
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