On/Off Switch; Ammeter; Decmotor Port; Ccd Port - Meade LX200 Instruction Manual

A connector for RS-232 communication even lets you perform
every function of the keypad from your personal computer.

ON/OFF Switch

When you move the ON/OFF switch (7, Fig. 8) to the ON
position, the power light indicator, current ammeter, and keypad
light up. The drive motors start, which momentarily pegs the
ammeter, then the drive motors shift to a slower speed, which
allows the R.A. worm gear to find its centering position for
calibrating the Smart Drive before returning to an even slower
tracking speed. The keypad display reads MEADE, then the
version of the software appears briefly before defaulting to
T E L E S C O P E / O B J E C T L I B R A RY. Within 15 seconds, the
planetary orbital calculations with their corresponding apparent
sizes and magnitudes and current stellar precession
calculations are made. Every computer function is checked,
and the LX200 diagnostics are complete.

Ammeter

The ammeter display (1, Fig. 8) is a series of vertical red LED
bars. Each bar that is fully lit represents 0.3 Amp (300 milli-
amperes) of current draw. The LED ammeter represents its
lowest value on the extreme left of the scale. During normal
tracking speeds, the ammeter shows about three fully lit LED
bars and, at times, a fourth that is partially lit, indicating about
900 to 1000 milli-Amps or 0.9 to 1.0 Amps of current draw
(when a slew is initiated the ammeter pegs the scale,
momentarily showing the inertia load; this effect is normal).
The current draw information can be useful if you are trying to
calculate how much battery life you will have during an
observing session. For example, if the ammeter has four bars
lit, indicating 1.2 amps, and you are using a 12-amp-hour
battery, divide 12 by 1.2 to indicate a battery life of 10 hours.
DEC MOTOR Port
The DEC MOTOR port (11, Fig. 8) is a DB-9 socket, designed
to accept the supplied coiled cord. One end of the coiled cord
plugs into the power panel; the other plugs into the DEC.
MOTOR socket in the right fork arm to power the Dec. motor.

CCD Port

The CCD Port (10, Fig. 8) allows direct interface from popular
aftermarket CCD autoguiding/imaging cameras with their
compatible connecting cables to accomplish autoguiding for
non-attended astrophotography. The CCD cameras effectively
watch a star and detect slight movements. When star
movements are detected, signals from the CCD electronics
make drive corrections in the LX200, to bring the star to a home
position.
Most CCD autoguiding/imaging cameras are supplied with a
cable that is compatible with the LX200 port. If your CCD unit
does not have a cable, one can be obtained from the CCD
manufacturer, or you can make your own cable using the
following table.
CCD
Connector Pin
#1
#2
#3
#4
#5
#6
LX200
Assignment
Normally Closed
West
North
Ground
South
East
Power 18 vDC Port
The power 18vDC port (9, Fig. 8) accepts either the standard-
equipment AC converter or the optional DC power cord. The
acceptable voltage range (under load) is from 12 to 18 volts.

Keypad Port

The keypad port (6, Fig. 8) is a 4-pin phone jack connector
socket, designed to accept standard 4-pin phone jack cords.
One end of the supplied coiled cord plugs into the keypad port;
the other end plugs into the LX200 keypad.

Reticle Port

The Reticle port (5, Fig. 8) accepts optional accessory corded,
plug-in style illuminated-reticle eyepieces, such as the optional
Meade 12mm illuminated-reticle eyepiece or the Meade Series
4000 Plössl 9mm illuminated-reticle eyepiece (corded style).
These let you set brightness and on/off pulsing rates from the
LX200 keypad.

Focuser Port

The Focuser port (4, Fig. 8) accepts optional accessory corded,
plug-in style electric focusers, such as the Meade #1206
Electric Focuser. These let you set electric focus from the
LX200 keypad.

RS-232 Port

The RS-232 port (2, Fig. 8) provides for personal computer
interface. This allows 9600 baud communications to access
every feature of the LX200 keypad. Many popular astronomy
programs directly interface with Meade LX200 telescopes.
These include Meade's Epoch 2000sk Sky Software.
APPENDIX F provides a wiring schematic to make the RS-232
cord, a cord test program, a demonstration program, and the
LX200 command set for writing programs. Meade supplies this
information for professional programmers. Meade does not
offer support or advice for writing software for the RS-232
option.
Field De-Rotator (FDR) Port
The field de-rotator port (3, Fig. 8), for use in ALTAZ, lets you
use the optional #1222 Field De-Rotator for long-exposure
astrophotography by eliminating the image rotation inherent in
altazimuth tracking.
12 vDC Output (Fan) Port
The 12vDC Output port (8, Fig. 8) is used to power the fan
located on the optical tube assembly (OTA). This fan evacuates
the warm air trapped inside the tube, allowing for faster cool-
down.
CAUTION: This port can be used to power other 12-
volt accessories, but maximum current output is
250mA.Do not attempt to use devices,such as heated
dew shields, which draw more current than 250mA;
they may damage the LX200 electronics.
This fan is controlled from the keypad, under TELESCOPE
functions. The 12vDC Output port lets you operate the fan
remotely from a PC.
The fan takes warm air from the OTA so that cool air can enter
the OTA through the filtered hole (20, Fig 1) at the bottom of the
OTA. The input filter prevents dust from entering the OTA.
Periodically replace the filter by removing the four bolts holding
the grill. The fan also has a filter, but this filter keeps dust out of
the OTA while the fan is off; it should not need replacing.