Bisque TCS - physics.muni.cz

Bisque TCS - physics.muni.cz
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Technical Documentation
Revision 1.0.6
Copyright © 2004-2007, Software Bisque, Inc.
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Introduction ...................................................................................................................................... 5
What is the Bisque TCS? ............................................................................................................ 5
History of the Bisque TCS........................................................................................................... 5
Can the Bisque TCS be used on my telescope? ........................................................................ 5
What is the cost of the Bisque TCS? .......................................................................................... 5
What is included with the Bisque TCS? ...................................................................................... 5
Brushless DC-Servomotors .................................................................................................... 7
Precision Gear Reducer.......................................................................................................... 7
Software Features ........................................................................................................................... 8
Minimum System Requirements ................................................................................................. 8
The Bisque TCS with the Demo-Drive ............................................................................................ 8
Taking the Demo-Drive for a Spin............................................................................................. 10
Mechanical Considerations................................................................................................... 10
Integral Gearing between Motor and RA Worm ................................................................... 11
Motor and Reducer Assembly .............................................................................................. 11
Worm/Gear interface............................................................................................................. 12
Mounting the Home Sensor Interrupters............................................................................... 12
Mounting the Sensor/Interrupter.................................................................................................... 13
Inside the Bisque TCS Control Box........................................................................................... 13
The MKS 4000 Main Controller board ...................................................................................... 14
Mount Type ........................................................................................................................... 15
Mount ID................................................................................................................................ 15
Maximum Speed ................................................................................................................... 15
Track Rate ............................................................................................................................ 15
Non Sidereal Rate................................................................................................................. 15
Minimum Limit, Maximum Limit ............................................................................................ 16
Guider Speed........................................................................................................................ 16
Compute................................................................................................................................ 16
Sensor Hour Angle and Sensor Declination ......................................................................... 16
Save in Flash (Single Axis) ....................................................................................................... 16
Home (Single Axis) ............................................................................................................... 17
Defaults (Single Axis)............................................................................................................ 17
Home After Link .................................................................................................................... 17
Focus 1, Focus 2 .................................................................................................................. 17
Training PEC ............................................................................................................................. 18
Recording the Periodic Error ......................................................................................................... 18
The PEC Dialog .................................................................................................................... 18
Recording Corrections................................................................................................................... 19
Curve Fit: Smoothing the PEC Table ........................................................................................ 20
Uploading the Smoothed Curve to the Bisque TCS.................................................................. 20
Apply PEC ................................................................................................................................. 21
Copy .......................................................................................................................................... 21
Paste ......................................................................................................................................... 21
MKS Status Dialog .................................................................................................................... 21
The MKS Advanced Dialog Box................................................................................................ 22
MKS 4000 Wiring Table & Harness Guide: ................................................................................... 23
Inside the Bisque TCS Enclosure ............................................................................................. 24
Six-conductor power connector ............................................................................................ 24
Motor cables ......................................................................................................................... 24
Bisque TCS Utility Software .......................................................................................................... 26
Bisque TCS Parameters Dialog Box ......................................................................................... 27
Edit ........................................................................................................................................ 27
Export.................................................................................................................................... 28
Import .................................................................................................................................... 29
Setup Dialogs ................................................................................................................................ 29
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Gear Ratio Setup....................................................................................................................... 30
Exercise..................................................................................................................................... 31
Set Index Angles ....................................................................................................................... 31
Appendix A – USB Driver Installation and Use ............................................................................. 32
Minimum Requirements for USB Control .................................................................................. 32
USB Driver Installation .............................................................................................................. 32
Notes ..................................................................................................................................... 32
To Install the MKS 4000 USB Drivers................................................................................... 32
To Uninstall the MKS 4000 USB Drivers .............................................................................. 35
Using the MKS 4000 USB Port ................................................................................................. 36
Determining the MKS 4000 USB COM Port Number................................................................ 36
Changing the MKS 4000 USB COM Port Number.................................................................... 37
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Introduction
What is the Bisque TCS™?
The Bisque Telescope Control System™ (Bisque TCS™) is a powerful nexus of world class
observatory control software and a robust dual axis motion control system. Together, these
components offer an unprecedented off-the-shelf telescope control solution. This research grade
controller is used in hundreds of observatories throughout the world in the Paramount ME Robotic
Telescope Mount, and has been installed on numerous other telescopes.
History of the Bisque TCS
The control electronics for the Bisque TCS were first introduced with the Paramount GT-1100S in
1999. Since that time the controller has gone through two major design changes, each time
reducing the number of parts. The first version, the MKS-3000, consisted of three boards—an
adapter panel, and one board for each axis. The MKS-3200 combined the individual boards for
each axis into a single board. The MKS 4000 was introduced in July, 2004 and reduced the
electronic component count by over 40% and added a USB interface.
Frequently Asked Questions
Q. Can the Bisque TCS be used on my telescope?
A. Because the Bisque TCS uses DC-servomotors with a very large dynamic range, the Bisque
TCS is applicable to a very wide variety of telescopes. However, certain parts of every
telescope system must be suitable to robotic control, the most important being the gears and
gear-to-worm interface. If the telescope system has an older model controller, then most of the
work is done and adding the Bisque TCS should be straightforward. The suitability of the
control system must ultimately be determined by the user.
Q. What is the cost of the Bisque TCS?
A. The Bisque TCS is available in two different models, and the cost depends upon the size of
your telescope.
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Standard Edition ($5000)
The Bisque TCS Standard Edition includes the 100 oz-in gear reducer/DC servomotor drive
system for 0.40 m (16 in.) and smaller telescopes.
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Professional Edition (Call)
The Bisque TCS Professional Edition includes the 300 oz-in gear reducer/DC servomotor
drive system for telescopes greater than 0.40 m (16-in).
Q. What is included with the Bisque TCS?
A. The Bisque TCS includes the following components.
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MKS 4000 Main Controller with
o Two axis motor controller for use with brushless servomotors.
o Autoguiding capability
o Focuser control
o 2 General purpose i/o ports
o Homing sensors for each axis
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o PEC storage in flash memory
o Temperature sensor
o Temperature compensated oscillator
Adapter/Power supply Panel that accepts 48V DC input.
48-Volt DC power supply
Two brushless DC-Servomotors with a nominal 10:1 reduction ratio.
Dual axis joystick.
Homing sensor cable with two home sensors.
Two motor extension cables.
Software Bisque Observatory Control Suite including TheSky, CCDSoft, TPoint and
Orchestrate.
Figure 1: The Bisque TCS Control Box.
The Bisque TCS has a multi-purpose interface board that supports all of the following
connections/operations:
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9-pin serial communications to attach the control system to the computer (or) USB
port (requires bridge software drivers to map as a COM port).
Joystick connection (RJ-12) to a dual axis, single button joystick.
48-volt power supply connector.
Speaker used to indicate completion of the initialization, homing process, and various
error conditions.
12 volt, DC-motor focuser port.
3 LED status indicators.
Auto-guider port.
Flash programming dip-switch.
Auxiliary input/output port.
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Figure 2: 100 oz-in. DC servomotors.
Brushless DC-Servomotors
The Bisque TCS comes with two Pittman Elcom brushless DC-servomotors. Each motor has a
built-in encoder with 2000 counts per revolution. The encoder wheel is made of metal instead of
plastic. The standard motor is capable of producing about 10 oz-in of torque over the entire speed
range.
Figure 3: Precision gear reducer.
Precision Gear Reducer
The motors are mounted to precision gear reducers with two steps of gear reduction. The first
step is 3.3333:1, and the second is typically 3:1. This combined reduction offers a very efficient
10:1 reduction yielding approximately 250 in-oz of torque to the worm.
Q. What is the availability of the Bisque TCS?
A. Bisque TCS delivery times are generally 3 weeks or less from the time the order is placed with
Software Bisque.
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Software Features
The Bisque TCS comes with the most complete set of support software available. The main
control is included in TheSky astronomy software, the world’s leading software for telescope
control.
A telescope fitted with Bisque TCS becomes an advanced robotic machine, with capabilities
rivaling or exceeding many major observatories.
• Real-time graphical display of the telescope position in TheSky.
• Simple point-and-click selection of any desired celestial object or position in the sky.
• Slew nearly a million deep sky objects from dozens of different catalogs, or choose
from several stellar catalogs including GSC or UCAC2 or USNO.
• Superb pointing by accessing the fully integrated “TPoint” telescope modeling
software.
• Improved tracking accuracy by utilizing the multi-order polynomial periodic error
correction algorithm in TheSky, or the user can modify using external software.
• Fully scriptable operation using Orchestrate scripting software. Choose lists of
objects or create mosaic areas of the sky.
• Autoguiding port compatible with SBIG and other guiding cameras.
• Slew to the any of the known solar system objects including over 250,000 minor
planets.
• Precise telescope tracking.
• Supports both German equatorial and fork type mounts.
• Set tracking rates to comets, minor planets and many satellites.
• Joystick or software button motion control.
• User definable soft-limits for collision avoidance.
• AutoHome capability lets you start up each night pointing exactly the same as the
previous night.
Minimum System Requirements
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Computer running Microsoft Windows (Windows XP Professional is strongly
recommended).
Power: The supplied 48V power supply draws about 2 amps while slewing.
The Bisque TCS with the Demo-Drive
Demo-Drive is a collection of hardware that provides a full functional worm to gear drive train
prototype (see Figure 4). The Demo-Drive not only demonstrates that the Bisque TCS works (to
perform slewing, tracking, homing, soft limits, etc.), it also provides a physical model on which
you can base your telescope retrofit.
If desired, Software Bisque will send you the Demo-Drive system. A $100 security deposit will be
refunded when the hardware (less the Bisque TCS) is returned.
Note: The following is applicable when the Bisque TCS is shipped with the Demo-Drive
hardware.
The Demo-Drive is a set of low-precision gears and brackets that are connected to the Bisque
TCS to demonstrate the motion of the DC servomotors, the implementation of the high-precision
gear reducers, and the operation of the homing sensors.
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The Demo-Drive was specifically designed to address questions and problems that arise when
mounting a dual axis control system to a telescope mount. Please carefully study the behavior of
the Demo-drive using TheSky astronomy software and the included the Bisque TCS Setup
software before attempting to use it on your telescope.
Figure 4: The Bisque TCS with the Demo-Drive hardware.
Four cables depart from the Bisque TCS main controller box, two motor cables and two sensor
cables. In the Demo-drive, some of the cabling is hidden inside of the Bisque TCS enclosure. The
white metal brackets serve the purpose of holding the precision gear reducers. The gear reducers
are black-anodized aluminum and they hold the motor and offer first reduction stage.
In a typical installation, the 60-tooth by 3/8th inch wide pulley
must be precision bored to fit onto your worm gear instead of the
demonstration plastic worm. The pulley has a 0.25” bore.
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Taking the Demo-Drive for a Spin
Plug in the 48V power, the joystick and a serial or USB connection (USB connection requires the
drivers are installed).
Now, turn on the Bisque TCS with the main power switch. You will hear the motors start to move
as they search for the encoder index mark. Each axis will deliver a short beep when the index
mark is found.
If instead you hear a single beep and followed by no motor motion, then see the troubleshooting
section.
You can now home the system by pressing the button on the joystick two times. The homing
process involves rotating the worm gears (in this case the black plastic demo-worms) until the
attached interrupter under the gear goes between the infrared sensor and receiver. The controller
goes back and forth several times to determine the position of the interrupter accurately. Once
this process is complete, you will hear three beeps (for each axis) indicating the homing process
is complete.
You can set parameters on the control system such that homing is not required to slew the mount
using the joystick or external control program.
Mechanical Considerations
A gear ratio range of 2000:1 to 8000:1 should be targeted for each axis of the telescope. For
example, if the worm-gear has 360 teeth, then a 10:1 reduction between the DC-servomotor and
the worm interface will provide a 3600:1 reduction.
Following is a formula for computing the arcseconds per tic encoder tic:
Arcseconds per tic = 1,296,000/(2000 * ratio)
Where 1,296,000 is the number of arcseconds in 360 degrees and there are 2000 encoder tics
per single motor revolution. The following table shows the size of the motor step size for several
gear ratios. Also shown are the maximum slew speed, the total encoder tics per telescope
revolution and the encoder tics/second at sidereal speed.
Gear Ratio Arcseconds Degrees/
Maximum slew
per encoder motor rev speed Degrees/
second
tic
2,000.00
0.324
0.18
11.9
2,400.00
0.270
0.15
9.9
2,800.00
0.231
0.13
8.5
3,000.00
0.216
0.12
7.9
3,600.00
0.180
0.10
6.6
4,000.00
0.162
0.09
5.9
5,000.00
0.130
0.07
4.8
6,000.00
0.108
0.06
4.0
8,000.00
0.081
0.05
3.0
Total Tics /axis
revolution
4,000,000
4,800,000
5,600,000
6,000,000
7,200,000
8,000,000
10,000,000
12,000,000
16,000,000
Sidereal
tics/second
46.423
55.708
64.992
69.635
83.561
92.846
116.058
139.269
185.692
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Integral Gearing between Motor and RA Worm
It is also required that the gearing between the motor and the worm is an integral value. If it is not,
the periodic error correction function will not work properly. For example, if the motor-worm ratio
is 5.387645:1, then each revolution of the worm will end up in a different motor position, and any
periodicity in the system cannot be accounted for.
It is highly recommended that clutches are eliminated or positively attached. The integrity of the
entire point/tracking system relies on the gear-sky relationship remains constant and clutches
break-down this relationship.
However, if the system will be used for visual observations or the operator is present to for
performing periodic telescope “datum corrections” or “star synchs” then the controller can be set
up to be used in a free form fashion. Soft limits will no longer be valid and the operator is
responsible for avoiding collisions.
Note: The control system should work well on pressure wheel and harmonic drive systems but to
date has not been implemented and tested.
Motor and Reducer Assembly
The motor reducer assembly must be firmly attached to the mount or worm block assembly, then
connected to the worm drive using a timing belt. The timing belts used on the reducer are 0.080”
(MXL) belts with a 3/8” width. The pulley provided for attaching to your worm is a 60 tooth pulley
that attaches to the 20 tooth pulley on the gear reducer providing the final 3:1 reduction.
The timing belt for the final reduction is not provided as the length is unknown. The belt included
on the reducer was provided by Stock Drive Products (www.sdp-si.com). Search for Belts, Timing
Belts then use the qualifiers 0.080” (MXL), 3/8th inch wide, Neoprene and you will be presented
with a list of the available lengths. The belt included has this part number:
A 6Z16-077037
The belt length or number of grooves is specified by the 077 portion of the part number. The
length of the belt is 0.080” * 77 grooves or 6.16” long. The belt required for attaching the reducer
to your worm will probably be longer.
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The motor has an 18 tooth pulley, part number:
A 6A16M 018DF9506
This pulley has 2 flanges, 18 grooves, 3/8” width and a 6mm bore. If replaced with a 20 groove
pulley, the first stage reduction is 3:1 instead of 3.33333:1, possibly providing more options for
the 3rd reduction stage, keeping in mind that the reduction must remain an integral multiple if the
periodic correction will be used.
The included pulleys have a small bore and must be precision bored to fit onto the worms of your
telescope mount. These pulleys were also purchased from Stock Drive Products and have the
part number:
A 6A16-060NF3708
This part number indicates the pulley is for 3/8th inch belts, has 60 grooves, made of aluminum
and has no flanges (NF).
Worm/Gear interface
The most critical and most error-prone mechanical problem faced when attaching a motion
control system to a telescope’s mechanical drive is worm to gear interface. It is recommended the
worm is spring loaded into the gear to reduce the backlash to a very small amount. Several arcminutes of backlash in the system will cause numerous productivity problems such as difficulties
guiding. TPoint will not be able to make the telescope point well, motion can occur during an
exposure that is random in nature and small slewing or tracking adjustments will be lost.
Mounting the Home Sensor Interrupters
Night to night consistency is extremely important in an observatory setting. The homing function
of the Bisque TCS was developed to increase productivity by eliminating the need for nightly star
synchronizations. One additional benefit of the homing process is it can be used to quickly
recover from a power outage.
The Homing function aligns the telescope axis to precisely the same point each time the mount is
homed. This is done by a multi-step process of locating the edge of an interrupter that is opaque
to the infrared sensor used by the control system.
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Mounting the Sensor/Interrupter
The goal of the sensor-interrupter pair is to have the sensor blocked at the end of travel of the
axis. The homing function will always rotate the gear towards the homing edge of the interrupter.
If the sensor is not blocked, it will rotate in one direction to find the “Home Edge”. When it is
blocked it rotates in the opposite direction to find the “Home Edge”.
The radius of the interrupter arc should be as large as possible because the further from the axis
of rotation the greater the movement is for small rotation angles. The homing is multi-step
process, and the first step is accurately locating the edge of the interrupter.
It is also recommended to make the interrupter subtend a large angle so that the homing position
is somewhere high in the sky rather than near the horizon. This is merely for convenience so that
long slews are not required to reach the imaged portion of the celestial sphere.
Inside the Bisque TCS Control Box
The Bisque TCS Control Box’s steel enclosure has dimensions of 6.8” x 6.4” x 2.1” (17 cm x 16
cm x 5 cm). Inside of the enclosure there are two electronic boards, the main MKS 4000
controller and the adapter/power board.
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The MKS 4000 Main Controller board
Inside the enclosure, the main controller has 5 cables attached to it. The include the RA and
Declination motors, the 26-conductor ribbon cable to the adapter panel, the 6-conductor power
cable to the adapter panel, and the sensor cable.
The Expansion Header is currently not used and exists for future use.
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The Bisque TCS Control System Dialog Box (TheSky)
Figure 5: Setup Tab’s on the Object Information dialog box
The Setup Tab allows you to change numerous options/parameters that effect the operation The
Bisque TCS. It is recommended that you are very careful making changes to any of the values
unless you have a clear understanding of how the change will effect the mount’s operation. For
example, if you set the Minimum Limit to –4,000,000 instead of -3,250,000, the mount may collide
with the right ascension stop if the mount is under joystick control or PC control.
Note that the two dialogs boxes pictured above show the Right Ascension and Declination default
settings for a particular German Equatorial mount.
Mount Type
Two options are supported, German Equatorial and Fork. If the German Equatorial mount is
chosen, the software will flip at the Meridian when necessary.
Mount ID
This information is for reference purposes only.
Maximum Speed
Depending on the gear ratio, the motors are capable of moving the telescope at up to 10 degrees
per second. For many telescopes, the desired maximum speed is much slower.
Track Rate
This input allows you to alter the tracking speed from the sidereal speed. A value of 100% will
rotate the mount at the sidereal rate.
Non Sidereal Rate
If you wish for the mount to slew at a rate that is separate from the sidereal rate but cumulative to
it, you can enter a value here in arcseconds per second. If you choose a minor planet and select
Set Tracking Rate from the Telescope tab, the non-sidereal rate will be set in both right ascension
and declination. To set the tracking rates back to normal sidereal, simply click on a star and
choose Set tracking rates.
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Figure 6: Click Set Tracking Rates to track on minor planets, planets or comets.
Minimum Limit, Maximum Limit
You can set the software limits for each axis to insure the telescope does not attempt to slew
through a hard stop. The right ascension limits are visible by looking at the South side of the
mount. The declination hard stops are set at –90 declination (or 90 declination for those “down
under”). When set properly, it is impossible to run the mount into a stop as the motor will
decelerate to internal limit.
Guider Speed
This option adjusts the speed at which guider corrections move the motors. The units are fraction
of sidereal rate so 0.50 is half of the sidereal rate.
Compute
This button simply computes the integer sidereal rate and displays it on the setup dialog for
diagnostic purposes.
Sensor Hour Angle and Sensor Declination
When the Sync button is clicked, the hour angle and declination of the Home Position are
computed and stored in the flash memory of the control system.
If for example you click Sync from the Telescope tab when the telescope is actually pointed to a
star other than the one shown in the Object Information dialog, then these values will be incorrect.
Note that the following three options work on a single axis basis. If you change the maximum
slew rate percentage for right ascension and then choose Save In Flash, only the right ascension
axis is changed and stored.
Save in Flash (Single Axis)
When changes are made to the values on the Setup screen, they will remain active until the
mount is powered down unless Save in Flash is chosen. It is important to note that while the
values are saved into flash memory, the motors are stopped briefly. This does not mean that
position information is lost, just that the telescope will stop tracking at the sidereal rate
momentarily. If you are positioned exactly on an object before you store the information in flash
memory, you will have to re-slew to the object once you leave the Settings Dialog.
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Home (Single Axis)
Select this command to home a single axis.
Defaults (Single Axis)
Selecting this command sets all of the values for the control system to the defaults values for the
Paramount GT-1100S.
Home After Link
If this option is selected, the mount will automatically home when a link is established between
TheSky and the telescope. This option can be potentially dangerous in settings where the
telescope can hit the roof of the observatory when it is not open. It should only be used when the
telescope is free to home regardless of the state of the enclosure.
Focus 1, Focus 2
Each time the focus control is used in TheSky, the Bisque TCS will pulse the DC focus motor for
a specified period of time. On the focus control there are two settings, slow and fast. You can
change the number of milliseconds each pulse lasts by entering the values here.
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Training PEC
The Bisque TCS has advanced Periodic Error Correction capability. The majority of periodic error
comes from the worm gear and the associated pulley system driving the worm gear.
Great pains must be taken in manufacturing and assembly to reduce the magnitude of the
periodic error in any system. Additionally, the worm and gear should be smooth—a necessary
requirement for any periodic error compensation function to work effectively.
Though PEC training and playing algorithms exist on many telescopes, few have the ability to
show the training data and then the ability to fit a smooth curve to the data. By exploiting the
computing power of the personal computer, the PEC algorithm of The Bisque TCS can provide
better and more consistent results than those running in a small microprocessor.
Recording the Periodic Error
Recording the periodic error involves guiding on a star using a CCD camera or manually making
adjustments for one worm revolution. The best results come from a CCD camera because it is not
subject to fatigue during the multi-minute recording period, and centroids of the guide star can be
computed more accurately with a CCD than a human eye.
Figure 7 — Periodic Error Correction tab on the MKS 3000 dialog (TheSky)
The PEC Dialog
The PEC dialog for The Bisque TCS provides the following:
• A graphical display of the current PEC table read from flash –OR- a graphical display
of the recorded telescope movements.
• A polynomial curve fitting function for producing a smooth PEC table.
• A real time display of the current “PEC Index” as the worm goes through a revolution.
• Guide-speed telescope adjustments for RA and Dec for manual PEC training.
• The ability to Copy the recorded table to the clipboard (for pasting in Excel for
example) and to Paste a Text table from the clipboard.
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Recording Corrections
During the recording phase, the angle of the worm, relative to where it would be during normal
sidereal tracking, is measured and stored at a rate of about 5 times per second. The recording
then provides a history of the angle-adjustment for a complete rotation of the worm. Note that this
function is for correcting periodic error only, and if the mount is not well polar aligned it will not
also introduce any drift into the system.
The following steps are necessary to successfully train PEC:
1. Start autoguiding: Start auto-guiding using a suitable guide star near the Celestial
Equator. Periodic error shows its greatest effects within the range of +15 degrees
declination and –15 degrees declination. Choose a star high in the sky (near the
meridian) to reduce atmospheric effects. Shooting on the West side will insure you do not
run into the dreaded “East Limit” of German Equatorial mounts.
2. Start recording: With the telescope initialized and running, display the PEC dialog in
TheSky by clicking Telescope | Options | More Settings, then selecting the Periodic
Error Correction tab. With the autoguider performing guiding corrections, click Record
on the PEC dialog. It is always good to guide for a couple of minutes first to insure the
system is settled and all backlash has been taken up.
3. Finish recording: Wait until the red status line has cross the entire graph (about 4
minutes) and the text on the Abort button changes back to Record. When this is
completed the recorded table will be displayed.
4. Smooth recorded table: Click Curve Fit to smooth the curve. You can select different
“orders” for the polynomial fit. (Orders of 5-7 seem to provide the best fit.)
5. Upload the PEC table to the Bisque TCS: Click Upload to copy the “smoothed” table
from the dialog into The Bisque TCS.
Note that the recording phase of the PEC training only records the values. It does not
automatically transfer the recorded table to the flash or activate PEC adjustments.
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Curve Fit: Smoothing the PEC Table
Unless the seeing is very good and the autoguiding settings are optimal, the recorded PEC
values will contain a considerable amount of noise and must be smoothed before the Upload
command is used to transfer the recorded table into the PEC memory on the The Bisque TCS.
Because there are typically several pulleys in addition to the worm on the mount, the smoothed
curve resulting from the noisy recorded PEC data will have higher order terms than a simple sine
wave. The Curve-Fit function will compute a least squares polynomial fit of the order entered in
the Polynomial order: edit control. The default order is 5th, which will typically result in a very
nice curve representing the recorded data.
It is important that the beginning and end values of the recorded table (that is, the left-most and
right-most values on the graph) are of similar magnitude. If they are not, it may indicate that the
polar alignment is poor, causing a significant drift during the recording phase.
The graphic above shows how the graphic will look after the Curve Fit function has been
selected. Both the original recorded data (the bumpy line) and the computed fitted curve are
shown. If it appears that higher frequency information is not modeled with the curve, you can
change the Order of the curve and experiment for a better fit.
The equation for the fitted line is also displayed at the bottom of the dialog once the Curve Fit
function is selected.
Uploading the Smoothed Curve to the Bisque TCS.
Once you have an acceptable fit to the recorded data, the new curve must be transferred to the
flash memory in Bisque TCS. When you choose the Upload command, you will be asked to
verify:
Choosing Yes will cause the smoothed PEC curve to be written to flash memory in the control
system. Next, the curve will be read in to verify the data was written properly. The control system
now holds the PEC table and can use it to reduce the effects of cyclical errors on your images.
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Apply PEC
The Apply PEC checkbox must be checked to activate the corrections. Even with a PEC table
present in flash memory, no corrections are made unless this option is selected.
The control system contains a parameter called the “PEC cutoff speed” that allows for setting the
speed at which the PEC table will be ignored. Turning off the PEC effectively sets this speed
zero, i.e. the PEC table is ignored at all speeds.
When the PEC table is activated, it is ignored at all speeds more than double that of sidereal
tracking. Interestingly, even small corrections of 3-5 arcseconds cause an audible (and somewhat
annoying) variation to the otherwise smooth sounding motors at higher speeds.
Copy
The Copy command simply copies the PEC values to the clipboard. These units of these values
are in encoder tics. The number of entries depends on the PEC ratio computed by the following
formulae:
125 *Pec Ratio
So if the PEC ratio is 10 (i.e. a 10:1 gear reduction before the worm) then the number of entries is
1,250.
The format of the data in the clipboard can be seen by Pasting the numbers into another
application like Notepad. It is a simple format, each of the entries are separated by a carriage
return/line feed.
Paste
This command will take a string of numbers from the clipboard and copy them into the Recorded
Table area. You can work to provide a better smoothing in another application or perhaps use
multiple tables to come up with a good weighted average. We have found the smoothed tables
generated from different parts of the worm to be very similar in shape.
MKS Status Dialog
Figure 8 — The Status Tab of the MKS 3000 dialog (TheSky)
21
This dialog is provided simply for diagnostic purposes. The encoders’ position (in encoder tics) is
shown for each axis. Other status values are shown that indicate the state of the motors and
control system.
The graph near the bottom of the dialog is a very small sampling of the encoder positioning vs.
desired encoder position.
The MKS Advanced Dialog Box
Figure 9: The Advanced Tab of the MKS 3000 dialog (TheSky)
Most of the values on this dialog are intentionally not accessible. The values present on this tab
of the dialog are critical to proper operation of the mount and should never be altered unless the
reason for making the change is perfectly understood. To gain access to the all of the inputs in
the Advanced tab, press and hold Ctrl+Shift the first time you click on the Advanced tab.
22
MKS 4000 Wiring Table & Harness Guide:
W4 26-pin connector (J3 MKS to J5 on the Adapter Panel)
RX_ADP serial
1
2
TX_ADP serial
DGND
3
4
MP/MC
(joystick 1)
5
6
(joystick 2)
7
8
joystick button
+5
9
10
DGND
RA LED
11
12
MP/MC_2
DGND (GUIDER_GND)
13
14
Dec LED
(RA FOCUS A )
15
16
(RA FOCUS B)
Dec FOCUS A
17
18
Dec FOCUS B)
(GUIDER_RA_UP)
19
20
(GUIDER_RA_DN)
(GUIDER_DEC_UP)
21
22
(GUIDER_DEC_DN)
(BUZZ1_A)
23
24
(BUZZ1_B)
(BUZZ2_A)
25
26
(BUZZ2_B)
23
Inside the Bisque TCS Enclosure
To remove the cover on the Bisque TCS enclosure, you must remove the 6 black Philips screws
(three per side) on each side.
Sensor cable
Some of the Sensor Cables do not have a notch in the 16-conductor
connector. To determine the correct orientation for insertion, look for
Pin 1 which is marked with a small triangle on the connector. Pin 1 is
connected to the brown wire on the multi-colored ribbon cable. Only
pins 1-8 of the sensor ribbon cable are used.
Six-conductor power connector
The 6-pin power cable can be plugged in backwards so make note of
it as well. The smooth side of the white connector goes TOWARDS
the 6 finger retaining clip. Do not orient the side with the visible
conductors towards the retaining fingers. The adapter cable is
notched so it can only go in one way (unless you push hard, so make
a visual check of where the notch goes).
Note that the smooth side of
against the black retention
(Adapter and Main
are visible on the side
the connector must go
fingers on each end
Controller). The contacts
opposite the smooth side
26-conductor ribbon cable
This cable is tabbed on each end so there is only one way to insert it into the
controller board and the adapter board. Important note: There are two
possible places to insert this on the controller board. Make sure you insert it
into PL-10 (labeled Adapter Board).
Motor cables
There are two motor cables plugged into the
main controller card. To remove these, you
must squeeze locking mechanism to release
24
the cable from the connector on the board. Removing the motors requires a firm squeeze and
a firm pulling motion to remove from the board.
25
Bisque TCS Utility Software
The Bisque TCS Utility Software is designed to allow access to the many settings in the MKS
4000 controller. Though the majority of these parameters do not require alteration from the
default values, this utility allows the inspection and editing of the values, and it provides a short
description of each.
The Bisque TCS application should be unzipped into TheSky6 folder on the computer. The first
step is to choose the Com port that will be used under Utilities | Set Comm Port.
Note: if you will be accessing the Bisque TCS via the USB port, please read the appendix A USB
driver installation for information on installing the USB drivers. The USB will map in as one of the
Comm ports, and you will also enter that port number here.
26
Bisque TCS Parameters Dialog Box
This dialog lists, for each axis and for global parameters, information about each of the MKS 4000
parameters. The radio button at the top is used to toggle between the RA axis, Dec axis and the
Global settings. The “Current Value” column is read from the controller. The other columns
(Default, Minimum and Maximum) are there for reference purposes. You can highlight each
parameter in the Parameter column and a short description of the purpose of that parameter is
shown near the bottom of the dialog.
As stated earlier, don’t be daunted by the number of parameters as only a few of them need to be
changed for a custom telescope installation. Additionally, there are special dialogs that will help
you change the parameters that are commonly altered.
Edit
The Edit command will display a dialog that will allow you to change the currently selected value.
27
The Defaults button provides a choice of default values for several different existing telescopes.
Choosing one of these will reset all of the parameters to the default values for that particular
telescope.
Export
This command writes the parameters to a text file with the following format using an extension of
BSQTCS. Once you have entered all of the parameters and checked the functionality of the
system, it is recommended that you save the parameters to a text file for reference purposes or
possible recovery under the rare circumstance of flash corruption.
; Bisque TCS paramater file
Acceleration
Maximum speed
Index angle
Base rate
Min. position limit
Max. position limit
Non sidereal rate
Guide rate
PEC ratio
Focus pulse slow
Focus pulse fast
Home velocity high
Home velocity medium
Home velocity low
Home direction
Home sense
Home mode
Home required?
Home from joystick?
Home in-out-in
Home index offset
PEC cutoff speed
Max. voltage
Max. gain
Unit ID
EMF constant
Max. position error
Home sensor position
Base rate (% sidereal)
|
400|
| 1080000000|
|
1665|
|
-43067265|
|
-4960000|
|
1120000|
|
0|
|
-672926|
|
10|
|
0|
|
0|
|
660000000|
|
110000000|
|
3900000|
|
1|
|
1|
|
2|
|
1|
|
1|
|
1|
|
0|
|
0|
|
15|
|
150|
|
100|
|
72|
|
1000|
|
2.0000000|
| 100.0000000|
400|
1080000000|
225|
0|
-5460000|
1700000|
0|
438102|
10|
0|
0|
660000000|
110000000|
3900000|
1|
1|
2|
1|
1|
1|
0|
0|
15|
150|
100|
72|
1000|
0.0000000|
0.0000000|
28
Creep rate (arc-sec/sec
Guide rate (%sidereal)
Max slew speed
Fixed sensor position
Mount Type
Focus axis
Synch version
Tics/revolution RA
Tics/revolution Dec
Debug output?
Startup test Joystick RA
Startup test Joystick Dec
Startup test Joystick button
Startup test guider
Play guider sound
IR enabled
General purpose IO 1
General purpose IO 2
General purpose IO 3
General purpose IO 4
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
0.0000000|
0.5000000|
90.0000000|
0.0000000|
0|
0|
10000|
11520000|
-7500000|
0|
0|
0|
0|
0|
0|
0|
0|
0|
0|
0|
0.0000000|
0.5000000|
90.0000000|
0.0000000|
Import
The Import command can be used to reload parameters that were written by the Export
command.
Setup Dialogs
Since only a small number of the parameters need alteration for a given telescope system,
special setup dialogs are provided to make the setting of these values easier.
29
Gear Ratio Setup
Use this dialog to set the Tics per revolution for each axis. The number of encoder tics per 360
degrees must be entered so that TheSky can make accurate computations for slewing, tracking
and other rate settings.
The computation is straight forward as it involves just a few different numbers for each axis. The
motor has 2000 counts per revolution, so this must be multiplied by the remaining gear reduction
ratio. Typically this is the number of teeth on the gear times the gear reduction between the motor
and the worm. The gear reduction provided with the Bisque TCS is 10:1. If a pulley other than the
provided 60-tooth pulley is used on the worm, then the gear reduction ratio should be changed to
reflect that.
Once the values have been entered, choose Compute to determine the number of motor encoder
tics per 360 degrees. The correct sign for the value computed (i.e. positive or negative) depends
on the direction the motor is mounted. The east west toggle will change this.
On declination, determining this correctly before a test is difficult. It is recommended that you set
the tics/rev, then use TheSky to slew from the current position to a position higher in declination,
and see if the mount moves in the correct direction. If not, then change the sign of the Tics/rev for
declination.
30
Exercise
This dialog can be used to test the application of the motors to the telescope. Each axis can be
tested individually by entering a distance (in seconds or degrees) in the drop list, then pressing
the Add to position button. This button can be pressed multiple times and the slewing distance
will accumulate.
Use the Abort move command to abort a slew (or a home).
Set Index Angles
Each motor has a different index angle which is represented by a number between 0 and 1999.
This index must be set properly as the controller must know where the phases of the windings on
the motor are. These are factory set and do not need adjustment unless a new motor is used or
the controller board is replaced. In such cases, the new index angle must be programmed into the
MKS 4000 controller board.
Because a phase that is 180 degrees from the current phase is also a legitimate value, adding (or
subtracting) 1000 from the index value will also work. For example, 645 is the same as 1645.
31
Appendix A – USB Driver Installation and Use
Paramount ME and the Bisque Telescope Control System (Bisque TCS) products shipped after
July 1, 2004 come with the newer model MKS 4000 control system and include a USB hardware
interface port. If you wish to control the Paramount ME via USB, you must install USB drivers
first. See “USB Driver Installation” below for details.
The MKS 4000 can also be controlled via standard RS232 port, and does not require the
installation of additional drivers.
Minimum Requirements for USB Control
Here are the minimum requirements for controlling the Paramount ME through a USB port.
• Paramount ME Robotic Telescope System or the Bisque TCS using the MKS 4000
control system.
• TheSky6 Professional Edition version 6.0.0.25 or later.
• The MKS 4000 USB drivers (included on the Paramount ME System disc).
• USB port on your computer.
• One USB cable.
USB Driver Installation
In order to the USB port, you must first install the MKS 4000 USB software driver.
Notes
•
•
This driver does not need to be installed to control the Paramount ME via standard
serial (COM) port.
The USB driver was previously named “Bisque TCS,” so Windows may identify your
mount as such. The MKS 4000 USB drivers will control either device.
The MKS 4000 USB driver installer software is included on the Paramount ME System disc. Note
that TheSky6 Professional Edition version 6.0.0.25 or later must also be installed. The installer for
the latest TheSky6 update is available on this disc.
To Install the MKS 4000 USB Drivers
1. Insert the Paramount ME System Disc into your CD or DVD-ROM drive and wait for the
introduction screen to appear.
2. Click Install Software.
3. Mark the I Accept the Terms of the License Agreement and then click Next.
4. Click TheSky6 Update Installer and the follow the instructions to install the latest version
of TheSky6 Professional Edition.
5. Once TheSky6 update is complete, click the USB Driver Installer text or graphic to
launch the driver installer software.
32
6. Click Install to install the MKS 4000 USB to UART Bridge Controller Driver Set.
7. During driver installation, the following screen appears twice. Click Continue Anyway
each time.
8. Click OK on the on Installation Successful screen.
9. Restart the computer.
10. When the computer is restarted, plug the USB cable into the mount. The message
“Found New Hardware” should appear in the Task bar, and the Windows Add Hardware
Wizard should appear to complete the installation of the MKS 4000 USB drivers.
33
11. Select Install From a List or Specific Location (Advanced) and then click Next.
12. When prompted to specify where to search for the drivers, click Don’t Search. I Will
Choose the Driver to Install option. Click Next.
13. Select the Universal Serial Bus Controller from the Common Hardware Types list and
then click Next.
34
14. Click the Show Compatible Hardware option, then select the MKS 4000 USB
Composite Device from the list, and then click Next. You’ll be prompted to verify the
installation of the USB drivers. Click Continue Anyway twice to complete the installation.
The MKS 4000 USB drivers should now be installed and ready to use.
The following drivers are copied to the Windows System32 folder:
•
•
•
•
•
Slabbus.sys
SlabWH.sys
SlabWNT.sys
MKSUSBUn.u2k
MKSUSBUn2K.exe
To Uninstall the MKS 4000 USB Drivers
1. Click Start | Control Panel | Add or Remove Programs.
2. On the Add or Remove Programs window, select the MKS 4000 USB to UART Bridge
Controller and then click Change/Remove.
35
3. When prompted, click Yes to complete the uninstallation.
4. You’ll be notified when the “uninstall” is complete.
Using the MKS 4000 USB Port
After the USB drivers are installed and the computer is restarted, you are ready to control the
Paramount ME (or the Bisque TCS) via USB port.
1. Plug the USB cable to any USB port on the computer, and into the Paramount ME’s USB
port.
2. Launch TheSky6 Professional Edition.
3. Click Telescope | Setup.
4. After selecting Paramount ME by Software Bisque or the Bisque TCS by Software
Bisque in the Telescope or Control System group, click Settings.
5. The Windows operating system maps the MKS 4000 USB driver to the next available
serial (COM) port. Select this port from the COM Port list and then click OK. If you’re not
sure which port this is, see “Determining the MKS 4000 USB COM Port Number” on page
36 for details on how to do so.
Determining the MKS 4000 USB COM Port Number
The MKS 4000 controls system’s USB port is recognized by the Windows operating system as a
standard serial (COM) port using special software drivers. When the USB drivers are installed,
Windows automatically assigns the next available COM port to this driver.
You can determine the COM port number (or change it) using the Windows Device Manager.
Note that under Windows NT, 2000 and XP Professional, the user account must be a member of
the Administrator’s group to alter these settings.
1. Click Start | Control Panel | Administrative Tools | Computer Management.
2. Under Computer Management, open the Device Manager.
3. Open the Ports node on the right side of the Computer Management window. One of the
Port entries will read: the MKS 4000 USB to UART Bridge Port Controller (COM N),
36
where N is the port number that Windows has assigned to this device. Use this COM port
number in TheSky6 Professional’s Telescope | Setup | Settings dialog box.
Changing the MKS 4000 USB COM Port Number
To change the COM port number assigned to the MKS 4000 USB driver:
1. Follow the procedure above (step 1-3).
2. Right-click on the MKS 4000 USB to UART Bridge Port Controller (COM N) and then
click Properties.
3. On the MKS 4000 USB to UART Bridge Port Controller dialog box, click on the Port
Settings tab. Click Advanced.
4. On the Advanced Settings for COM N dialog box, from the COM Port Number list,
select the desired COM port to use for the MKS 4000 USB port.
37
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