JMI Telescopes MAX Computer User Manual
MAX Computer
Operator's Guide
Copyright 2005
JMI Telescopes
Jim's Mobile, Incorporated
8550 West 14th Avenue
Lakewood, CO 80215
U.S.A.
Phone (303) 233-5353
Fax (303) 233-5359
Order Line (800) 247-0304
Web Site jmitelescopes.com
Email sales@jmitelescopes.com
Table of Contents
INTRODUCTION............................................................................................................. 4
What is Does................................................................................................... 4
What it Doesn't Do .......................................................................................... 4
GETTING STARTED ...................................................................................................... 4
Encoder Test........................................................................................................... 4
Troubleshooting ...................................................................................................... 5
USING YOUR COMPUTER ............................................................................................ 7
ALIGN STAR or STAR FIX...................................................................................... 7
RA DEC................................................................................................................... 8
CATALOG ............................................................................................................... 8
NEW Catalog .................................................................................................. 8
PLANETS........................................................................................................ 9
GUIDE..................................................................................................................... 9
IDENTIFY................................................................................................................ 9
ALIGN ................................................................................................................... 10
Subsequent Alignments ................................................................................ 10
TIMER................................................................................................................... 10
ENCODER ............................................................................................................ 11
POLAR .................................................................................................................. 11
SETUP or INSTALL .............................................................................................. 11
About SET DEC=0, LEVEL ME, and VERTICAL .......................................... 12
Appendices
A. Specifications ....................................................................................................... 13
B. NS/DS Catalog Abbreviations.............................................................................. 14
C. RS-232 Cable Assembly....................................................................................... 14
D. Sample BASIC Program Listing .......................................................................... 15
E. Quick-Start Guide ..................................................................................Back Cover
INTRODUCTION
This manual covers the NGC-MAX, NGC-miniMAX and
NGC-microMAX computer units. Sections which cover
material not common to all of these units are labeled with
the models they apply to.
The MAX family of computers are revolutionary,
computerized digital setting circle units with an internal
database of hundreds to thousands of astronomical objects.
After a simple alignment process (pointing your telescope at
any two celestial objects, such as bright stars), the
computer will operate as a high-resolution, real-time display
of the Right Ascension and Declination of your telescope.
Due to the internal database of galaxies, clusters, nebulae,
stars, quasars, black holes and planets, the computer can
quickly guide both the novice and expert viewer alike to
almost any object desired. Instead of spending the majority
of your viewing session attempting to locate objects, you
can now be guided from object to object in seconds!
The MAX computer utilizes an 8-character (16 on the NGC-
MAX) dot-matrix LED display with brightness control and
four large push-buttons for the user-interface. All functions,
including selection of any one of the internal objects, can be
accomplished easily in a matter of seconds with very little
practice. After a brief familiarization period, most users will
be able to perform all operations by touch.
The NGC-MAX's serial interface allows communication with
external devices, opening the door to almost endless
possibilities. One application of this technology is our
popular SGT-MAX setup. This system allows users with a
personal computer to install a real-time link between their
telescope and desktop planetarium software, such as
T
HESKY™ by Software Bisque.
What it Does
The MAX computer will guide the user to celestial objects
by indicating the direction and angular separation for each
axis of the telescope mount. When guiding to the Orion
Nebula, the display might show the following:
M042 59→ 51↑
To break this down,
number 42 (the designation for the Great Orion Nebula),
59→ indicates the object is 59° to the right, and 51↑
indicates the object is 51° up. As the telescope is moved in
the directions indicated, these numbers will decrease
toward zero, at which point the telescope is pointed at the
desired object.
What it Doesn't Do
The MAX computer cannot physically move the telescope.
The user will normally need to move the telescope by hand,
although some telescopes have slewing motors which can
M042 represents Messier catalog
accomplish this task. (Some "Go To" telescopes can be
software controlled using the SGT-MAX system.)
GETTING STARTED
The first step in preparing to use your MAX computer is to
install the optical encoders onto the axes of your telescope.
If purchased with one or more sets of encoder mountings
from JMI, will find a separate Encoder Installation sheet
which covers the installation process required for your
specific mount. Most of these installations require no
drilling or tapping and can be installed in approximately 1520 minutes.
After the encoders have been mounted, a test should be
performed to confirm proper installation and function of
each of the two encoders, as well as the setup information
within the MAX computer. (When purchased with a set of
encoder mountings, the MAX computer is pre-programmed
with the necessary information to work with your specific
mount, so you should not need to concern yourself with this
aspect yet. For further information on this topic, see
SETUP on page 11.)
Encoder Test
Plug the common end of the encoder cable into the MAX
computer and each of the opposite two ends into its
appropriate encoder (the Encoder Installation sheet
indicates which end is for each encoder). Place the MAX
computer unit in its holding tray or on a stable surface out of
the way of the telescope's motion. The unit should be
turned off at this time.
Point your telescope at the zenith (directly overhead). Now
turn the MAX computer on. After the version number is
briefly shown, use the brightness button (found to the right
of the ON/OFF switch) to set the display brightness as
desired.
Press the DOWN button until
press ENTER. The display should now show one of the
following:
NGC-MAX
ER=000 ED=+000 000 +000
ER=000 ED=+090 000 +090
AZ=000 AL=+000
AZ=000 AL=+090
Note exactly where your telescope is pointed relative to
your mount (mechanical setting circles make this easier), as
ENCODER is displayed, then
NGC-miniMAX/microMAX
Page 4
you will want to be able to reliably return to this same
position in a future step.
Begin rotating your telescope in its Right Ascension or
Azimuth axis (left-to-right) in a clockwise direction as seen
from a vantage point directly above the telescope.
(Southern Hemisphere users should rotate in the opposite
direction.) The first set of displayed digits should increase
as the telescope is moved (you will see something similar to
000 ... 001 ... 002 ... 003, etc.). If the digits decrease
instead, see the troubleshooting guide for help.
If possible, continue rotating the telescope through a full
360° circle. Verify the accuracy of the display by comparing
it with the number of degrees you have moved in Right
Ascension or Azimuth. At 360° you will see
Return the telescope to its starting point by rotating counterclockwise. At this point the digits should return to
instead they vary from zero by more than plus or minus 1,
see the troubleshooting guide for help.
Now rotate the telescope in Declination or Altitude (up-and down) from the zenith toward the Southern horizon. The
second set of digits should decrease (Note: an apparently
increasing value is actually decreasing if the sign is
negative). If the digits increase instead, then see the
troubleshooting guide for help.
If possible, continue rotating the telescope through a full
circle. Return the telescope to its starting point by rotating
in the opposite direction. At this point the digits should
return to their original
from the original value by more than plus or minus 1, then
see the troubleshooting guide for help.
If you encountered no problems, continue on to the next
section, USING YOUR COMPUTER.
000 or 090. If instead they vary
359 or 0.
000. If
Troubleshooting
Use the Troubleshooting Guide (below) to find possible
causes then read the sections below for possible solutions.
For a more in-depth troubleshooting guide, see the
addendum Diagnosing MAX Computer System Problems.
Low battery. The MAX computer can be powered from
any 7-15 volt DC (direct current) source. When the power
supply is below about 6.5 volts, the display will flash
ENCODER ERROR.
If using an internal 9 volt battery, be sure that it is alkaline
("Alkaline" must appear on the battery casing). Due to
potentially rapid voltage and current drops in other battery
designs, they should not be used. This includes nickelcadmium (NiCd) rechargeable batteries as well as carbonzinc batteries).
Troubleshooting Guide
Symptom
The unit does not come on. • Low battery (use only
The display does not reflect
the motion of one or both
encoders.
One or both encoders
appear to run in the opposite
direction.
Moving telescope in one
axis changes opposite
encoder reading.
Bad warp factors, inaccurate
operation.
Display shows
ENCODER
ERROR at times.
Mechanical slippage. Verify that all appropriate
setscrews and bolts are tight. Any gears or belts should not
have slop (you should not be able to rotate the encoder
shaft without turning the telescope — a belt does not need
to be very tight to meet this criteria). You might want to
mark the encoder shaft to determine if it rotates with the
telescope as it should.
Incorrect encoder setup. Since the computer can be
used with various encoder resolutions and gearing ratios,
the software allows the definition of the resolution for both
axes. If this value is set improperly, the result can be
slightly to grossly inaccurate performance, and if set to zero,
can make an encoder appear to be non-functional.
A separate sheet titled JMI Encoder Setup Sheet — Tics-
Per-Revolution, included with your encoder mountings, lists
the correct setup to use with your specific mount. Confirm
that the MAX computer setup matches this sheet paying
particular attention to the order and sign of each tics-perrevolution specification (see SETUP on page 11 for
additional help).
Reverse mounting. If an encoder is running the
improper direction, the simplest solution is to change the
sign of that encoder's resolution as found in the setup (see
SETUP on page 11). This should only become necessary if
the encoder has been mounted in a manner contrary to that
which was intended by the Encoder Installation sheet, or if
the encoder installation is custom designed by the user.
Possible Cause(s)
alkaline batteries)
• Mechanical slippage
• Incorrect encoder setup
• Bad encoder/cable
• Reverse mounting
• Incorrect encoder setup
• "Hung" German mount
• Swapped encoder cables
• Not polar aligned
• Incorrect encoder setup
• Incorrect initialization
• Not polar aligned
• Slew rate exceeded
• Bad encoder/cable
• Low battery
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