Lacerta M-gen User manual

LACERTA M-GEN

Stand-Alone AutoGuider

User’s manual for Firmware 02.00

Created by: Zoltán Tobler at 9 June 2010

Last updated: 18 August 2011

Table of contents

1 ABOUT THE HARDWARE ............................................................................................................................... 3

1.1 PARTS OF THE DEVICE ..................................................................................................................................... 3

1.2 POWERING THE DEVICE ................................................................................................................................... 5

1.3 ELECTRICAL CHARACTERISTICS ...................................................................................................................... 6

1.3.1 Specification of the HC and Camera ...................................................................................................... 6

1.3.2 Imaging specification of the Camera ..................................................................................................... 7

1.4 TUNING ON AND OFF THE DEVICE ................................................................................................................... 8

1.5 UPDATE MODE .............................................................................................................................................. 8

1.6 HARDWARE TYPES .......................................................................................................................................... 9

2 NEW FEATURES IN FW. 02.00 ...................................................................................................................... 10

2.1 PREVIOUS VERSION CHANGES ....................................................................................................................... 11

3 ABOUT THE USER INTERFACE .................................................................................................................. 14

3.1 BUTTONS AND LEDS .................................................................................................................................... 14

3.2 MAIN CONCEPTION OF THE USER INTERFACE ............................................................................................... 14

3.2.1 Menus ................................................................................................................................................... 15

3.2.2 Variables (parameters) ......................................................................................................................... 15

3.2.3 Profiles ................................................................................................................................................. 17

4 PARTS OF THE SOFTWARE, FUNCTIONAL UNITS ............................................................................... 18

4.1 AUTOGUIDING FUNCTION (AG) .................................................................................................................... 18

4.2 AUTOEXPOSURE FUNCTION (AE) ................................................................................................................. 19

4.3 RANDOM DISPLACEMENT FUNCTION (RD) ................................................................................................... 19

4.4 FILESYSTEM (FS) .......................................................................................................................................... 20

4.5 COOPERATION OF THE FUNCTIONAL UNITS ................................................................................................... 20

5 MENU TREE ...................................................................................................................................................... 22

5.1 SCREENS AND FUNCTIONS DETAILED ............................................................................................................ 23

5.1.1 Autoexposure (AE) screen .................................................................................................................... 24

5.1.2 Random Displacement (RD) screen ..................................................................................................... 27

5.1.3 Misc. screen .......................................................................................................................................... 29

5.1.4 Power off screen ................................................................................................................................... 33

5.1.5 Guiding menu screen ............................................................................................................................ 34

5.1.6 Guider setup screen .............................................................................................................................. 35

5.1.7 Star Search screen ................................................................................................................................ 36

5.1.8 Live View screen ................................................................................................................................... 38

5.1.9 Guiding screen ..................................................................................................................................... 40

6 MORE ON CCD BINNING .............................................................................................................................. 47

6.1 DEMO IMAGES ............................................................................................................................................... 47

7 PRACTICAL EXAMPLES ............................................................................................................................... 50

7.1 ASSEMBLY AND STARTUP ............................................................................................................................. 50

7.2 FOCUSING USING LIVE VIEWS ........................................................................................................................ 50

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7.3 EXAMPLE FOR SETTING UP AND STARTING AN AUTOGUIDING ...................................................................... 51

8 ERROR CODES ................................................................................................................................................. 53

9 PLANNED DEVELOPMENTS ....................................................................................................................... 54

2

1About the Hardware

1.1 Parts of the device

The “LACERTA M-GEN Stand-Alone AutoGuider” (referenced as LMG) consists of the

following parts:

•Handcontroller (referenced as HC). It has the whole user interface (buttons,

indicator LEDs, LCD) and does the main functions like Autoguiding, Random

Displacement, AutoExposure etc.

The display is a graphic, 128x64 dot negative LCD with backlight. Previous

versions have red while the new ones come with amber (orange) color due to the

much better contrast.

Note that there is a protector film on the display window, You must remove it

before the first use! This is quite invisible in dark when the LCD backlight is on,

some can let it on to protect the window from scratching and remove only if too

much scratch is visible yet.

The connetor panel is located at the bottom of the HC box:

These are the following from left to right:

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oCanon EOS compatible shutter output (3.5mm stereo jack conn.)

oCamera port (RJ-45 type female conn., can be used any low resistance UTP

cable too but the supplied cable is preferred. Note: NEVER try to use a UTP

cross cable!)

oDC power input (5.5/2.1mm size) (12V nominal, 9-15V), tip positive

(polarity-protected)

oST-4 compatibles autoguider output (RJ-12 type female conn.)

oPC communication port (USB-B mini 5-pin conn.)

•Camera (head). This is a special device, can be used only with the LMG

Handcontroller. It’s function is imaging and doing several image processing steps.

To attach the Camare to the guider telecsope there is a 4-5mm thick T2

inside screw. Any T2→1.25” adapter can be used for 1.25” (31.7mm)

focusers. There is a 1.25” filter thread inside the T2 panel to attach some

filter or “dust preventor”.

At the back of the Camera there is the same type of connector as on the

HC (RJ-45 female).

The sensor is a high sensitivity monochrome CCD from Sony (with

ExView HAD technology). Due to its exremely low dark current (dark

noise) and the enhanced sensitivity in near infrared it doesn’t need cooling

and saves energy. These with the low readout noise gives the ability of

guiding on very faint stars or using small guidescope. The small pixel size

allows using shorter focal length for guiding compared to other systems.

(For more information see the datasheet of the CCD, its part number is:

ICX279AL-E. Some info can be found here:

http://www.sony.net/Products/SC-HP/datasheet/90203/data/a6805282.pdf)

Note: ont the CCD there is the protector film by default. You must remove

it before the first use! Cleaning the CCD’s glass is done as for any other

optical surfaces. Try not to scratch it! Don’t let any electrically

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conducting material or liquid fall into the circuit, on the CCD and its pins.

(The foam around the CCD gives some protection.)

•Supplied cables:

o1 piece of Camera cable (black), similar to a straight UTP cable. Used to

connect the Camera with the Handcontroller. It’s length is around 1.8-2m.

o1 piece of “ST-4 autoguider” cable (white) to connect the Handcontroller

and the mount with ST-4 compatible autoguider input. About 1.5 meters of

length.

o1 piece of USB-A (PC side) / USB-B mini5 (HC side) cable to the

connection with the PC. Used to update Firmwares, download data files or

control the HC.

o(Some release include an EOS shutter cable with 2.5mm and 3.5mm stereo

jack ending, 2m length. (Can be used directly for Canon EOS 350D))

1.2 Powering the device

In normal use : (during autoguiding)

The device needs a nominal 12V DC power source on the HC’s DC input connecor, which

is tip positive. This is essential for the Camera for imaging. 9-15V is also accepted but don’t

use higher voltage than 15V (peak voltage max. 18V)! The output power of the DC supply

must be minimum 2.4W (12V, max. 200mA/125mA), typically 1.6W is enough.

Be careful choosing the type of the DC power source, it MUST BE well stabilized or a

constant source. A battery, stabilized DC or switching regulator should be used! An

unfiltered, only AC-rectified power (which has a heavy transformer in it) may not supply the

device properly, this could lead to sudden reset/turn-off of the device or even damage the

input circuitry! (For example a 220V-input and 12V / 800mA-output rectified power supply

could easily source over 20V peak voltage at low load, which is harmful for the device!)

“ Logic only” mode : (USB connection: Firmware update etc.)

If the Camera is not connected or will not be used for imaing the USB bus can alo supply

the device’s logic circuit. All those functions are accessible that don’t need analog power

(imaging). Works for example: Autoexposure program, data file downloading, Firmware

updating but autoguiding (star search, LiveView etc.) will not.

NOTE: new type devices (boot version ≥ $14) may fail to update the Camera’s firmware

if the USB voltage is well lower than 5V. In this case, power the device also from its DC

input!

When the device gets power input (DC input or USB cable is plugged in) a short flash of

the four LEDs indicates this. The flash is also present at the Firmware update process when

the device is reset before the next update step.

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1.3 Electrical characteristics

1.3.1 Specification of the HC and Camera

Values for HC with BOOT version $14 or above (see ‘-v’ option in the App.)

Notes: currently the is no power saving features implemented.

All DC input current values are for a nominal 12V input. These currents

change with the input voltage.

Min. Typical Max. unit Notes

DC power supply 912 15 V 7

Active input current (no light)

(full light)

96 125 mA 1,3,4,5

109 125 mA 1,3,4,5

HC only input current (no light)

(full light)

27 mA 1

33 mA 1

Power-down mode with USB

w/o USB

10 mA

6mA

ST-4 out. pull-down current 5.3 mA 6

Shutter out. pull-down current 1.1 mA 6

1 with connection to PC via USB

3 ‘active’ means an active Camera (autoguiding or LiveView)

4 the value changes as some parameters do (gain, exp.time)

5 there is a fuse in the HC

6 for a TTL low input level

7 the peak input voltage MUST NOT exceed 20V!

Values for HC with BOOT version $13 or below

Min. Typical Max. unit Notes

DC power supply 912 15 V 7

Active input current 110-116 200 mA 1,2,3,4,5

HC only input current 27 mA 1,2

Power-down current with USB

without USB

9mA

6mA

RED display backlight 0 30 mA

AMBER display backlight 0 7 mA

ST-4 out. pull-down current 1.1 mA

Shutter out. pull-down current 0.5 mA

1 with connection to PC via USB

2 older devices may draw about 8mA more current due to the MCU

(see the table above for the other notes)

Note.: values shown gray are only informational and derived from the

design.

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1.3.2 Imaging specification of the Camera

ADU means: Analog to Digital conversion Unit (step)

e- means: electron

RMS means: standard deviation (statistical); Root Mean Square

Min. Typical Max. unit Notes

CCD active pixel area 752 × 582 pixel

3.65 × 2.7 mm

CCD pixel size 4.85 × 4.65 μm

Imaging depth 8 bit

Image conversion speed 2M pixel/sec max.

Conversion (min. gain (2))

(max. gain (9))

44 e-/ADU 1

1.75 e-/ADU 1

Readout noise at min. gain (2) 22 e- (RMS) 1

Readout noise at max. gain (9) 5.9 7.1 8.5 e- (RMS) 1,2,4

Average dark current 3.2 e-/px/sec 1,2

Pixel capacity 10k e-1

Operating temperature -10 60 °C 3

1 the value is only informative but measured on some instances

2 at 23ºC CCD temperature

3 violating the limits is the responsibility of the User

The CCD and its environment heats itself a little bit if active (good for anti-dew).

The power dissapated in the HC is also rather useful than problematic.

4 typical value (mean) measured on 22 pieces of ‘random’ Camera instances.

The mean of deviation of this value between the instances is only 0.29 e-.

The limits were measured in some “extreme” instances.

The gain of the CCD’s analog output signal is called ‘gain’ generally and can be set in

the HC as a parameter. The scaling of this is defined so that 2 steps means one

magnitude difference in sensitivity. The full scale (from 2 to 9) cover 3.5 magnitudes

(×25). The table below shows the physical imaging parameters for each gain value

(approximately):

gain conversion

(e-/ADU)

pixel saturation

(e-)

1 70.0 16700

2 44.0 10500

3 25.7 6660

4 17.5 4200

5 11.0 2650

6 7.0 1670

7 4.4 1050

8 2.77 666

9 1.75 420

Note: gain 1 is not available from FW v2.00 due to

possible early pixel-saturation

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1.4 Tuning on and off the device

After the device is first supplied with power source it goes to sleep (power-down) mode,

nothing can be seen and there are no output signals. The cables can be safely plugged in or

out.

Turning ON the device:

Press ESC button! The program will start in application mode if the HC contains valid

Firmware. The version of it is displayed for 2 seconds, then the first screen appears (see

later). You can skip 2 sec. waiting with pressing ESC one more.

If the device does not contain valid Firmware (or it was faulty) it starts in update

mode, which is shown on the LCD. In the center of the display there is a “NO FIRMWARE”

text indicating the case.

If ESC is pressed continuously for more than 1 second the device starts in update

mode (1.5). Using this starting procedure is not required because the updater (PC

application) will force to restart the device in this mode. If You happen to enter this mode,

hold down SET for 1 second and the Firmware will try to start. This works until the

device communicates through USB, after this only an USB command can start the

application (PC application has a command line option to do this).

From Firmware ver. 1.21 (or later) the device starts on the date and time settings

screen and the filesystem’s screen after that. This is needed to make You remember to set

or check the correct date and time at every startup and select a file to open if You want to

store data about the night (guiding, events etc.). If You don’t need these functions, two

more ESC keypresses after startup leads directly to the main menu.

Turning OFF the device:

In application mode: Navigate back to the main menu (with pressing ESC some times)

and select the power off item. It is essential to power off this way because it stops every

functional part properly (Camera), closes the open file and stores the parameter settings.

WARNING: simply plugging out the power cable is not recommended, mainly if the

Camera is actively working! Data loss or corruption in the open file or in the stored

parameters may occur.

If the device is in update mode and there is no operation in progress (mainly

Firmware update), You can power-off the device with detaching the power cable(s). (Be

sure there is no operation in progress shown by the PC application.)

WARNING: never plug out the power/USB calbe during Firmware update! Doing so

can damage the boot program and it may be required to reconfigure the device at factory

(it’s not the part of warranty).

1.5 UPDATE mode

Also known as BOOT mode. The device always starts in BOOT mode by pressing ESC,

but doesn’t start the firmware if You hold ESC button for more than 1 second. If there is no

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valid firmware on the device, UPDATE mode will start anyway with the text ‘NO

FIRMWARE’.

This mode is used to update the Firmware or download/refresh stored parameter data. The

PC application may make the running Firmware to enter this mode (even during autoguiding),

be careful! More on this at 1.4 or in the PC app.’s manual.

1.6 Hardware types

There are two types of hardware of this device (HandController and Camera). The newer

will show a little X right to the ‘UPDATE MODE’ text to indicate the hardware type. Besides

the HC will show a BOOT version of $14 and the Camera a version of $14 as well. (See PC

app.’s manual how to check this.) Lower BOOT versions indicate ‘old’ hardware.

Note that the new hardware can not run Firmware version older than 2.00 due to the

hardware change. Uploading such an old firmware will succeed but the HandController will

display ‘WRONG FIMWARE’ in update mode.

This is important only if You want to use different HC and Camera (not from the same

device pack). The HC and Camera is advised to be used always from the same pack, the

following configurations would work only:

Old HC, old Camera (with 8-wire (black) cable)

New HC, new Camera (with 6-wire (yellow) cable)

Old HC, new Camera (with 6-wire (yellow) cable ONLY!) – not guaranteed

All the other configuration MUST NOT be used since the devices may be damaged!

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2New features in Fw. 02.00

A short list about the main features compared to the pre-release (01.99):

oIt can handle the device with new hardware. (The new hardware is indicated by the

BOOT version number which is $14 instead of $13.)

oThe autoguiding (only) on RA axis is extended by a “DC-offset removal” (caused

by slow and large PE amplitudes).

oStar search function is bugfixed and works for all the binning modes, after

changing the binning and the ‘last results’ do also.

oNew LiveView mode: pixel averaging with maximum removal (also called as hot

pixel rejection mode average / ‘havg’). Useful to virtually remove disturbing hot

pixels but to hold faint stars on the screen.

oFixed bugs:

Star search data: the selected star’s brightness is displayed right in summed

ADU units (approximately, precision depends on many things).

LiveView’s exposure compensation is now good for all the binning modes.

When the guiding window changed its position, the pos.limit and inhibit

time (0.5 sec) was wrong.

and internal ones..

A short list about the main features of the pre-release (1.99) compared to the previous one

(01.22):

oHardware binning operation modes implemented into the Camera.

oAutomatic continuation of following the star (in the old position) after a LiveView

usage (without setting a new guiding position) when re-entering the guiding

screen.

oMore fine ‘LiveView dark compensation’. (Keeps the image vertically ‘flat’.)

oBlack level is set to the lowest giving more dynamic range to the photons.

oBetter CCD interlaced readout technique for more precise guiding frames.

o‘Camera OFF’ is displayed wherever is necessary.

o5th page (“extra”) is introduced for the guiding screen(s) (‘Guiding / Current

guiding’). The changes are:

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Camera can be turned ON and OFF manually on this page. The position of

the guiding window is memorized except between binning changes.

The ‘wait’ time variable is moved to page 5. (Most of the users don’t need

this at page 1.)

oThe guiding window display mode can be changed now from all the pages.

oThe guiding window display mode ‘maxY’ is renamed to ‘profile’ as the image

shown is the guiding image’s (vertical) profile. This is NOT a histogram.

oThe used threshold level is shown as an inverted horizontal line at the ‘profile’

display mode. (See above.)

oThe ‘drifts’ display mode uses ± 4 LCD pixels as the tolerance interval. If the drift

exceeds the display area (± 12 pixels for each axis) it means that drift reached the

‘emergency interval’, which is 3 times the tolerance interval.

oGuiding window is locked at guiding, otherwhise it follows the star.

oText (detailed) error display. (Except some rare cases.)

2.1 Previous version changes

From 01.22:

oThe AutoExposure’s state and outputs are also stored into the open file. The

guiding curve (“drifts”) is saved only when the AE is in the exposure state.

It belongs that the PC application version 1.22 generates a HTML format output

when downloading a file, which contains for all the exposures separately the

guiding curve as well as the spread of the guiding star positions and the

approximated tracking error of the mount (derived from the autoguider signals).

All the raw data is written into a CSV file for any user processing.

oThe calibration has been moved to a new screen, on which the directions, speeds

and the orthogonality is displayed.

oWhen starting the autoguiding the latest position is not rounded to pixel center but

used the raw position directly for the new guiding center.

From 01.21:

oThe menu structure has been changed a little bit. Some rarely used screen and

parameter is pushed “down the tree” while (for example) the guiding screen is now

accessible with only two SET keypresses from the main menu.

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oComplete file(system) menu screens: open, close, delete and create new, a short

file list and file details screen. The date and time settings screen is also accessible

now from menu.

oIn Autoexposure, selecting Start/Stop, Pause will change the selection to the more

understandable item.

oLCD contrast can be set (and is stored).

o“AstroTimer mode”: the Autoexposure’s and Random Displacement’s opertion

mode using an external shutter controller device. (This mode is fully compatible

with AstroTimer.) The Autoexposure will have only one time value (period) to set

while the external shutter is active and the shutter output will be only active when

a Random Displacement is being made (the AE program is in wait state).

oNew RD mode: besides the default “uniform square” there is a new “square snake”

pattern.

oExclusive autoguiding output signalling mode. (“Non-simultaneous signalling”).

Only one axis can have autoguiding signal active at a time, that’s why it is called

“exclusive mode”. Between different axis’ signal there is a 62ms dead time. This

may be used with “old, touchy“ mount that don’t tolerate the default parallel

signalling.

oBugfix : quitting from LiveView screen did not stop the imaging into the screen.

oBugfix : in some special cases the “guiding image” was drawn into false position –

even if it was inactive.

From 01.20:

oStepping back in menu tree will hold the priously selected item. It’s easier to re-

enter a screen if You had left it accidentally.

oThe method of calibration is modified: now it’s more immune to temporary star

lose, position evaluation bettered and the result’s precision (axis direction) is

displayed.

oModified RD method: it does not move the guide star to an exact position, instead

it moves it only “close to it” to minimize the dead time between the exposures

(that was rather long in wind or at bad seeing/parametrization).

oReal-time clock (0.1s resolution) and date to timestamp the data stored in the open

file.

oBasic filesystem (and selection only at startup). The open file will store the

guiding “drifts” and the calculated autoguider output signal lengths. To download

the files use the PC application v1.22.

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oBugifx : some more-byte parameters were not stored correctly at power-off.

From 01.12:

oThree profiles available now to store parameter settings individually. Can be used

as “presets” for separate guiding configuration (off-axis, guide scope(s) etc.);

oAG speed can be set independent for each axis with 0.01 step size (any non-

standard correction speed can be set);

oThe “drifts” history diagram is now displayed scaled to the tolerance value;

oPause/Continue button added to the AutoExposure screen – during paused state the

AE program parameters can be changed;

oAdditional wait time can be set between the guiding exposures letting the mount to

react before the next exposure. (Useful to lower the chance for oscillation.) – will

be obsolete, using the smart guiding method implemented soon.

From 01.11:

oNew “drifts” as a guiding display mode: the history of the drifts of the guiding star

can be monitored for the previous 48 frames;

oIncreased LCD backlight PWM frequency, it has no effect on the Camera now (in

LiveView had a tiny);

oBugfix: “Camera stop in cold” symptom has been corrected (in hardware too).

From 01.10:

oLiveView function (1:10 size real time image for the entire CCD field);

oTe “threshold” parameter is now set in pecentage;

oSme parameters can be changed with LEFT or RIGHT buttons too;

oAvanced method for StarSearch – overexposed stars are missed more rarely;

oTe brightness of indicator LEDs can be set individually;

oAsking for stopping the guiding if it’s in progress and some function needs to have

it stopped;

oAutorepeat for all the buttons – makes the navigation or parameter change easier;

oA 0.5s dead time for the buttons is inserted at the power off screen to avoid

accidental power-off of the device.

From 01.09 and before:

oAdoptation from the prototype circuit and software, hardware changes.

oIndicator LEDs are now active;

oBugfix : AutoExposure did short “wake-up” signals periodically in wait state;

o...and much more tiny changes...

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3 About the user interface

3.1 Buttons and LEDs

On the front panel of the HC there are 6 buttons and 6 so-called indicator LEDs next to

them. The buttons are for navigation and controlling of the device while the LEDs indicates

some action of it for visual checking.

These are the following:

oESC

Functions: back, cancel or exit.

Main function: exiting from the current screen.

blue LED indicator: shutter focus line active - feedback (default).

oSET

Functions: enter (into sub-menu), choose, set, activate, start editing.

Main function: activating the selected item on the screen.

green LED indicator: shutter exposure line active – feedback (default).

oUP, DOWN (arrows)

Functions: select prev./next item, inc./dec. digit (in editing mode), DEC manual

guiding.

Main function: navigation between the screen’s items.

red LED indicators: DEC axis correction line(s) active. (Shows what is physically

on the autoguider output).

oLEFT, RIGHT (arrows)

Functions: changing the value of the selected item, (select prev./next item,)

moving the cursor (in editing mode), RA manual guiding.

red LED indicators: RA axis correction line(s) active. (Shows what is physically

on the autoguider output).

3.2 Main conception of the User Interface

The display and controlling of the device is menu-based. By default there is always an

active screen, holding one selected item on it (for most of the screens). The selected item is

always shown inverse. (This is something like a cursor for the actual screen items.) The

selected item can be activated by pressing the SET button. Activating means entering to

editing mode (to change its value) or doing some function. By default You can change the

selected item (~”move the cursor”) with UP and DOWN buttons and in some cases LEFT and

RIGHT could also be used.

This “screenshot” below shows the main menu with the “Exposure” item selected on it:

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Certain items behave differently. There are number, time and text types etc. Text type

items can lead to a submenu or are to do some function (like a button), while other (number or

time) types store a value that could be edited/changed and are called parameters or variables.

These are to setup, parametrize the device, to control its behaviour.

For details of the method of changing the parameters see 3.2.2.

3.2.1 Menus

The HC has a fixed menu tree structure. From the main menu every submenu is

accessible with a subscreen at the end that is for some specific function. If an item leads to an

other (sub)screen it is called menu item.

Exiting from a screen is done with ESC button. When entering into a subscreen, the

selected item is memorized to set it as the selected item if You go back with ESC.

3.2.2 Variables (parameters)

There are many types of items on the screens. If an item holds a value its called variable

or parameter. Their value can be changed in editing mode. For demonstration there are some

examples:

Example

A variable item is selected on the screen.

By pressing SET You can enter editing

mode (if it is allowed to be changed). The

bracket around the edited item indicates

the editing mode.

SET

Beginning of editing.

In this mode there is always a cursor that

selects one digit and is shown inverse. To

move the cursor on the digits LEFT and

RIGHT buttons can be used.

LEFT

Moving the cursor.

To change the value of the selected digit

use UP and DOWN buttons. Use

autorepeat of the buttons for faster

changing of the digit value.

UP

(more times)

Increasing a digit.

To store the new value press SET again.

The new value immediately takes place

in most of the cases. Doing so we also

leave the editing mode. SET

Storing the new value.

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To discard the new value edited (to hold

the old one) press ESC. This exits editing

mode. ESC

Discarding the new value.

The editing process is always done on a temporary variable so it does not affect anything if

You start an editing and then exit from it with ESC. During editing the device uses the

old/original variable value.

Types of the items or parameters:

•Decimal

An integer value representing something (meant in some unit or indexes different

modes). Consists of fix number of digits (all these digit characters are shown

inverse when selected as above in the example), has limits (minimal and maximal

value). (If a limit is violated in editing mode by changing a digit’s value the value

is set to that limit independent of the edited digit.)

The example above shows this type of parameter.

•Real

Real value with two-digit fractional part. Edited the same as for the decimal type.

Between the integer and fractional parts there is a dot character.

For example:

The selected “AG speed RA” item in this screen

is real-type with a value of 0.5.

•Time

The default time-type variable is always meant in 0.1 sec unit and is displayed this

way.

For example:

The selected “exp.time” item on this screen is

time-type with a value of 3 minutes and 15.2

seconds.

In editing mode it behaves as the decimal type except that some digit’s maximum

is only 5 (ie. 59 for the minutes) and there are dot and double dot characters

between the digits.

•Text

This type can not be edited as the other. Holds a fix text or the ‘value’ (state) of it

can be changed with the SET button. So the text can show the value or state of a

parameter.

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Can be a so-called button item that does/starts

some function. Can be a submenu item to enter a

new screen (down in menu tree).

For example the main menu consists only of this

type of items.

Can be a so-called switch that can be altered by

the SET button. (This is a two-state parameter

item.)

For example: enabling functions or modes are

controlled by this type of items. Commonly a ‘-‘

character indicates the OFF and a ‘’ char. the

ON state.

Can be a special parameter that can have a few

number of fix values, displayed as a text.

For example on LiveView screen this item can

have only the “max.” and “avg.” values.

The value of most of the parameters or variables are stored into EEPROM (non-volatile)

memory of the HC at power-off. At the next power-on they are initialized from here.

3.2.3 Profiles

Profile means the value of a set of variables / parameters, these are called profile

variables. The value of these can be set in each profile independently. Changing the active

profile will change the value of all these profile variables.

There are 3 separate profiles (number 0, 1 and 2). The active profile can be changed in the

misc. menu screen. If doing so the old profile setting is stored into memory and the new one is

loaded into the profile variables. The change of these takes effect immediately and so there

may be a question to stop the current autoguiding because all the guiding parameters are

profile variables.

A profile can be interpreted as a ‘trimmed’ set of parameters for each guiding solutions,

for example profile 0 for a guiding telescope, profile 1 for off-axis system and so on.

Non-profile (global) variables are not affected by a profile change. The parameters of the

AutoExposure program are of this global type for example. Profile variables are generally for

those variables that are needed for autoguiding.

17

4 Parts of the software, functional units

There are some well defined functional units in the device. In the next sections You can

read about these functional units for the sake of a better transparency.

4.1 AutoGuiding function (AG)

The main function of the device is Autoguiding. It has its own process (runs

independently of the other (including the User Interface)), handling the Camera is it’s job

exclusively so the program of the Camera is the part of this functional unit.

The guiding star’s image is processed by the Camera. The guiding program in the HC uses

the calculated star position to control the mount with the ST-4 compatible autoguider port.

There is a dedicated screen for Autoguiding, on which everything can be controlled that

directly affects guiding. This is the guiding screen, can be reached with two SET keypresses:

(Main menu) Guiding → (Guiding menu) Current guiding →

Guiding screen is indicated by a “GUI” text in the top right corner and a 48x48 pixel

window monitoring something on the left of the screen. There are more pages of this screen,

Lacerta M-GEN User manual

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