2.1. System description

The autoguider system consists of a CCD detector mounted in a Peltier cooled enclosure within the A & G box at each focal station of the telescope. Each CCD head has its own dedicated CCD controller. All the CCD controllers are connected to a single VME rack which runs the autoguider application. Commands are sent to the VME system from either the Utility network, or via an optional engineering terminal. The output of the VME system is a graphic display showing the CCD image, pointing errors and statistics, and a stream of error coordinates to the TCS.

2.2. Using the Autoguider via the Network

With this version, the autoguider is now able to be used without any need to access the engineering terminal. The engineering terminal interface in its Observer mode drives the autoguider by running the network routines locally, no additional functionality is available there. Engineering commands, with a Forth style syntax and according freedom from error checking aera available for non operational tasks. The network commands are described in section 7.1.1. See the document WHT-AUTO-3 for a description of the syntax used to drive the autoguider system from ICL.

2.3. Loading the system

The system will load a Forth Version 3 kernel from Eproms on the processor board. This then loads block 9 on the hard disk which starts with a RELOAD instruction. This reload loads a more detailed kernel with the Forth Version 4.2.3 system from a boot image on the hard disk pointed at by block 0 location 0. This is normally block 2000 or 10,000. The rest of the software will load, displaying comments indicating progress. At the end of the load sequence, the user is prompted to choose the telescope focus in use, this will initialise the CCD controller and system variable for this application. The system is then ready to use.

2.3.1. Normal Boot Procedure

Before booting

Make sure that all of the serial ports are connected: two at the rear of the VME rack and one for each focal station on the front, plus one for the TCS link. There should be one Fibre Optic cable plugged into the FOX chassis for each focal station.

Turn the power on if it is not already on. If the power is on, press the bottom switch on the Ironics system controller card at the extreme left hand edge of the VME rack to reset the system. The OPAL card should have a flashing green LED on the front and the display should go bright blue. The software should start to load from the Quantum hard disk on power up.

At this point, the engineering terminal should display the system banner with the Forth version number: V3.1b ,( this is NOT this software version) the date and time and shortly the the prompt "About to load A/G code". If you wish to load from a backup disk, press control-C now to abort the load sequence and follow the backup version load sequence described below.

Messages will appear as the various program modules load. As each module loads, a count of each group of blocks in the module is output, if the module has loaded normally, then the count should be 0, at the end of each line. Here is the output from a successful load sequence.

ImageForth/68 Cambridge Version 3.1c 20 Oct 93

Time 10:23:05 About to load A/G code

Loading Utilities s/w 0

Loading Network s/w 0

Loading serial comms s/w 0

Loading Old CGI s/w 0

Loading Image Stack s/w 0

Loading Autoguider s/w

Loading CCD controller iface 0

Loading main a/g code 0

Loading ag-network interface 0

Loading user interface 0

Loading vocabulary switches 0

Loading sealed vocabulary 0

Autoguider loaded. - Initialising system initalising display

probing for CCD controllers

Controller status head

Cass not connected 1

UES not connected 1

Prime not connected 1

initialising CCD controllers type OBSERVER to seal vocabulary again

AUTOGUIDER>

NOTES: In this laboratory setup, no ccd controllers were connected. This was detected and the system initialised for UES use. It has been arranged in the lab version for the system always to use the Cassegrain fibre head code. It is assumed that the CCD controllers will use the flow sensor and cool the chips automatically.

The software detects automatically which controllers are connected and initialises all those connected. The status of the ports can be displayed with the .CONTROLLERS command. This implementation is more robust than the previous one. If a controller is plugged in with the system running, then selecting that application will cause the controller to be initialised and added to the database.

2.3.2. Loading from a backup disk.

In order to run the system with a previous software version, or from a backup disk, abort the load sequence at the message "About to load A/G code" by typing control-C.

to use a version from a INSITE disk: enter INSITE 0 DRIVE 1000 LOAD

to use the previous version of software : enter 11000 LOAD

to use this version : enter 1000 LOAD

2.3.3. CCD fibre header codes

The data which comes from the CCD controllers via the optical fibres has a header code associated with it to identify the correct source. This is set with headers on the fibre transmitter board in each controller. The header codes are shown in table 1 below. These are set using link J14. A header installed is a logic 0 and a header not installed is logic 1 with the MSB nearest the fibre tranmitter. Diagrams for the Three controllers are also given below. Note that the AutoFib instrument uses the Prime controller.

Table 2. CCD fibre header codes

Cassegrain                 0x70                                    
UES                        0x60                                    
Prime                      0x80

2.4. Switching between the current version and the previous version

The system which is loaded on power up or reset can be easily changed in the same fashion as with the DMS. The version which is loaded is defined in block 9. To select the correct version, enter either RUN-RELEASED or RUN-DEVELOPMENT as appropriate.

2.5. Autoguider serial port connections

The connections for the CCD controller serial lines are as shown in the diagram below.

2.6. Using the autoguider from the Engineering terminal

The new D-task is now available and ICL commands should be the normal means of controlling the Autoguider. All of the Autoguiding functions are available via this route.

The engineering terminal can control the autoguider in the same fashion and high level command procedures acting like ICL procedures have been written to implement an observers user interface from the engineering terminal. There are two vocabulary search paths available from the engineering terminal, via the OBSERVER and ENGINEER words. The Observer commands are limited in scope to one vocabulary, SEALED which contains links to those commands used to control the autoguider system in the normal course of events. All of the commands available in the SEALED vocabulary have been specifically written to take their paramters AFTER the command, to resemble ICL command input as closely as possible. Errors in command names or prameter values are reported as such.

The ENGINEER vocabulary is not actually a vocabulary but a word which alters the dictionary search path to include all of the autoguider source code dictionaries. Thus after typing ENGINEER, all of the commands for both low and high level operations are available. Note that the high level user interface commands will still work in their usual way, with parameters last, but the rest of the commands will work in the normal Forth fashion.