CSO

OPTICAL ALIGNMENT

SYSTEM

 
 Rosemary Glendinning  and  Lynn Holt  and  Mac Cooper

January 1998
Table of Contents

Notes
Introduction to the CSO Optical Alignment System
 

DRAWINGS
Overview, Controller #1 & #2 -------------------------
Overview, Controller #3 -----------------------------
Motor Control Wiring (opto-isolator) -------------------
Controller #1 Module connections ----------------------
Controller #2 Module connections ----------------------
Controller #3 Module connections ----------------------
5th Mirror Encoder and limit connections (B3 #1 )-----------
4th Mirror Encoder and limit connections (B3 #2) ----------
Receiver #1 & #2 Encoder and limit connections (B3 #34) ----
Chopping 2nd Encoder and limit connections(B3 #5) ---------
Chopping 2nd Field Wiring Terminal (FWT) ---------------
 

Appendices
Appendix A.  File list
Appendix B.  Old method of talking to SMCs
Appendix C.  Stepper Motor Controller #1 & #2 Wire List
Appendix D.  Stepper Motor Controller #3 Cable list
Product Literature

Introduction to the CSO Optical Alignment System
Beam Path
The beam path for the heterodyne receivers begins with the sky and hits the primary mirror, then back to the new chopping secondary, then to the cass focus area where it either hits the teritary on the relay optics mount or the main tertiary which redirects the beam to the sidecab through the elevation axis tube. When all is operating correctly the beam is collimated and concentric with the telescope elevation axis through the elevation axis tube. It next hits the 4th mirror and is directed to the 5th mirror just outside the receiver local oscillator beam splitter.
If the relay optics mount is in place and the main tertiary is manually moved out of the beam, then the beam is reflected to a 4th and 5th mirror in the relay optics mount and then to a bolometer device (sharc) or heterodyne such as the 850 Rx or some guest instrument like hertz(chicago group). There are other mounts that can replace the relay optics including the FTS and SUZIE mounts.

What optical elements are controlled by this system
At this time (Jan98) the chopping secondary, 4th mirror, 5th mirror and relay optics rotators are all controlled by the three stepper motor controllers (SMCs). Each SMC has 6 axes of control, but we are currently using the 6th position in each SMC for the RS-232 IO communications to the antenna computer. In 1998 the controllers will end up in the new antenna computer and talk directly on the VME bus, so that will free up 3 additional axes for control. See below for a list of which components are controlled by each controller axis.

Rotators on the Relay Optics Mount at the Cass focus area
Each of the two instrument mounting positions on the relay optics mount is capable of being rotated approximately 300 degees. This allows array instruments to rotate with the field of view as the telescope tracks the source.

 

SMC #1

  SMC #2

  

SMC #3

  

Drive Directions

Positive step direction commands to the drives will cause the following physical moves: Controller #1 Controller #2 Controller #3

Appendix A - File list of drawing files.

Directory of C:\ACAD\LYNN

 
 
FILENAME IN ACAD
DESCRIPTION
MCDBPAN .DWG 28,500 DB 25 pin panel layout
MCSUB .DWG 42,337 Motor control sub assemblies LED mezzanine board schematic
MCWLB34 .DWG 63,472 Side cab BOB #4 - Sony linear encoders Axes #6 - #10
MCB31 .DWG 31,739 Fifth mirror BOB #1 - Rotary encoder, limits, and power supply interconnect Axis #2
MCWLB35 .DWG 52,940 Chop 2nd mirror BOB #5 - Sony encoders on 2nd mirror Axes #11 - #14
MCWLB33 .DWG 40,787 Cass Relay optics BOB #3 - both rotators on relay optics mount Axes #3 - #4
MCPAN .DWG 23,312 Front panel layout for VME cards DCX VM-100 mechanical
MC1BLK .DWG 17,404 Block diagram of Motor controller #1 with Axes #1 - #5 (rotaries)
MC2BLK .DWG 19,038 Block diagram of Motor controller #2 with Axes #6 - #10 (linears)
MC3BLK .DWG 22,956 Block diagram of Motor controller #3 with Axes #11 - #14 (rotary and linear)
MC2NDFWT.DWG 10,569 Chop 2nd field wiring terminal Axes #11 - #14
MCOV .DWG 6,681 Overview of any typical axis
MCSCFWT .DWG 10,729 Side cab field wiring terminal Axes #6 - #10
MCCFFWT .DWG 10,249 Cass focus relay optics mount field wiring terminal Axes #3 - #4
MCSCH2 .DWG 71,685 Motor controller #2 VME schematic and mezzanine boards
MCSCH3 .DWG 66,138 Motor controller #3 VME schematic and mezzanine boards
MCB32 .DWG 26,454 4th mirror BOB #2 encoder, limits, and power supply interconnect
MCOPTSC .DWG 65,258 Motor Control opto isolator - all channels
MCSCH1 .DWG 65,764 Motor controller #1 VME schematic and mezzanine boards
 

Appendix B - Using the old manual system for talking to the SMCs.

Note: to use any of these procedures the SMC serial line you want to use will have to be disconnected from the antenna computer and connected to COM2 (9-pin D connector on an option card, side of the machine not COMMs on the back) of the Toshiba laptop computer.

Basic Reporting Commands
N = Motor Axis ID number, e.g. 1, 2, 3, 4, or 5 for each controller.

NTP Tell step Position in motor steps( e.g. 2TP with Toshiba serial connected to SMC1 = 5th rotary position)

NTO Tell encOder position count( e.g. 2TO with Toshiba serial connected to SMC1 = 5th rotary encoder count)

NTS Tell Status -- reports a decimal number. Convert to Hex and refer to table on page 30 of the manual.( e.g. 10 = trajectory complete, motor on.)

TMn Tell Macro displays the current macro stored in position n of macro memory

VE VErsion gives the version revision of the ROM code

 Resetting to Datum Position To reset step and encoder count at a known position datum if encoder count has been lost (through resetting or power cycling) and you want to move to a new known position.

Type in the following sequence of commands for each axis:

 N= Motor Axis ID number, e.g. 1, 2, 3, 4, or 5 for each controller.

 

u 1. First move to a position you know to be on the negative step side of the index position. NTP read current step position (this will be 0 following reset). NMAn (n = desired step position, e.g. 2MA-3000 ) move to a new step position. It is wise to increment the move in small chunks (e.g. 1 or 2000 for linear drives, 5000 for radials) and check for position by eye until you are sure you are on the negative step side of the encoder index or datum position.

Datum is when the Set P-15 (hall effect switch) is just next to the magnet indicator block.

On the 5th rotary it is marked with a pencil line and an arrow showing direction of positive moves.

On the 4th rotary there are two pencil lines; one on the encoder mount and one on the encoder coupling.

 u 2. Once you are in a safe starting position type the following commands: NSIn Set the initial velocity. The drive will move at 1/10 this speed. n should have the following value for each drive. A1 (4th rotary) 200 (e.g. 1SI200)

A2 (5th rotary) 400

B2 (5th horizontal) 101

B3 (5th vertical) 101

B4 (4th linear) 101

 NFI0 (zero not O) Set Find Index. This enables encoder reset at index.

NFE0 (zero not O) Find Edge. This starts the hunt for index.

If anything goes wrong at this point type NRT. This is the only command that will halt a datum move and it will also lose all the encoder positions and setups for that control card. Try to avoid getting problems on datum.

u 3. Immediately after datum has been found:

 NFI1 De-energize the index hunt for encoders;

EM1 Execute macro #1 (assuming the macros are loaded).