900GTO, 1100GTO, 1200GTO, 1600GTO, 3600GTO and the
feature high-quality DC servo motor drive electronics, the rugged GTOCP3 Control
Box and our GTO handheld computer Keypad for GoTo operation. These sophisticated,
versatile mounts can be operated with the GTO
handheld computer keypad alone or in conjunction
with various popular software packages on your
Windows-based or Mac computer or mobile smart device.
The GTOCP3 Control Box contains all of the circuitry to drive the two servo motors and the logic required to circumnavigate the sky. It functions as "the brains" of your mount translating the commands that are received from external software (Keypad, planetarium program or other software) into electrical signals to the motors to produce movement and other critical functions. It also makes all the required calculations and determines the safe and proper path for GoTO slews.
The main function of the GTO Control Box is
to drive the R.A. and Dec. motors, which are DC
servos with built-in shaft encoders. The rotation
rate and precise number of rotations of each motor is controlled
with a servo feedback loop. The servo looks at the return
pulses from the shaft encoders and adjusts the
current to the motor so that the rate is identical
to the commanded rate (i.e. from .25x sidereal
to 1200x sidereal). The precise number of motor rotations is translated
into incredibly accurate R.A. and/or Dec. distances.
This electronics box is mounted directly on the R.A. axis of the 1200 and 900 mounts (as shown in the photo), on the side plate of the 1600 and 3600 and is a stand-alone unit for the Mach1, 1100, 400 and 600E mounts. The freestanding unit attaches to your pier or tripod with the handle on the fabric pouch or the Control Box Adapter (CBAPT) both included with the Mach1GTO.
The GTOCP3 shipped with the Mach1GTO mount is completely black-anodized to match the mount. The control boxes shipped with the 900GTO, 1100GTO, 1200GTO, 1600GTO and 3600GTO mounts have a black-anodized panel where the connectors are located and the remainder of the box is painted the same cream-white as the mounts.
| Control Features
The command language protocol that is programmed into the microcontroller of the GTOCP3 Control box allows the sophisticated control functions of your mount. Please keep in mind that the software that communicates with the mount will determine which commands are utilized. For instance, although the control box is programmed to include a command that can implement a timed guide move, if the software does not issue the command, this feature cannot be used.
For optimum utilization of the advanced functions in the command language protocol, we recommend that you control your mount with either the GTO Keypad, software that utilizes the ASCOM V2 driver or the Astro-Physics Command Center (APCC) when it is released. All of these control options were written by Astro-Physics. For more information, see: Control Your GTO Mounts with Your Keypad, Computer or Mobile Smart Devices.
Here are some of the key features and functions available in the GTOCP3 Control Box:
| Mechanical Features
|Dimensions of servo box||4.9" x 4.9" x 1.8" (12.5 x 12.5 x 3.4cm)|
|Weight||1.5 lbs. (0.7 kg)|
|Suggested power sources||Portable 12V battery pack, auto or marine battery
110 to 12V DC Power Supply (5 amp minimum, regulated and well-filtered to prevent spikes), like our 13.8-volt, 5-amp power supply (PS138V5AC) . For the 1200GTO mount with a heavy load in colder climates and for the 3600GTO, we recommend the 15-volt, 12-amp power supply (PS15V12AC)
|Standards||Meets FCC and CE standards|
Astro-Physics GTO Servo Motor Drive System - Model GTOCP3 - Manual
Upgrade and Purchase Information|
The GTOCP3 can be purchased as an upgrade for your GTOCP1 and GTOCP2. This link provides important information for people who want to know how the GTOCP3 differs from the earlier control boxes and the specific items that they need to purchase. If you currently own a GTOCP3, you may also purchase a second one as a backup, if you wish.
The Keypad is a self-contained handheld computer that allows you to control all essential telescope functions and includes an extensive database of objects. We have designed this unit to be as intuitive and easy to use as possible, while filling it with terrific features to make your observing session productive and pleasurable.
Most buttons are assigned to one function only. You do not have to remember shift key patterns or complex keystroke sequences. The directional buttons are shaped like arrows to help you find them in the dark without looking at your keypad. The stop button is readily accessible if you need to cancel any slewing request immediately.
The menu system is very easy to navigate. Each 4-line screen will display several choices which correspond to a number button. Simply press the number button to initiate the command, e.g. "1=M, 2=NGC." When you press "1" the Messier entry screen will display and you can enter the number of the object that you wish to see. Press GOTO, which will cause the mount to slew. The <PREV and NEXT> buttons will allow you to scroll quickly through the lists of common names or from one menu to another.
You will be very pleased with the intuitive operation of this controller. There are no complicated sequences of keystrokes to remember. It is so easy to use that even if you don't use it for a few months, you will feel at home with the Keypad very quickly.
|Dimensions||7.2 x 4.1 x 1" (181.6x104.1x24.6mm)|
|Weight||1 pound 8 ounces, including cable and KEYPRO (680 grams)|
|Red LED fiber optic backlit, alphanumeric|
|Display screen||4x20 character alphanumeric|
|Pre-defined Tracking Rates||Sidereal, solar, lunar and stop (Note: lunar rate is R.A. only, and does not include the moon's movement in declination.)|
|Rate selections for Auto-guider port||0.25x, 0.5x, 1x|
|Pre-defined Direction Button Rates||
0.25x, 0.5x, 1x, 12x, 64x for centering and manual guiding.
600x, 1200x for rapid button movement. (Actual rates will be slower for 3600GTO mounts and for older 400GTO / 600EGTO mounts with the 32:1 gearboxes. Keypad display will still read 600 or 1200 – see below for actual rates)
|Pre-defined Rapid GoTo Slew Rates - All 900GTO, 1200GTO and Mach1GTO||600x, 900x and 1200x ( top speed - 5 degrees per second)|
|Pre-defined Rapid GoTo Slew Rates - 3600GTO and 3600GTOPE||300x, 450x and 600x ( top speed - 2.5 degrees per second)|
|Pre-defined Rapid GoTo Slew Rates - 400GTO and 600EGTO with 32:1 gearbox||590x, 860x and 980x (Top speed dependent on available voltage from power supply. Note that these rates differ from those in the GTOCP2 - 460x, 580x, and 675x)|
|Pre-defined Rapid GoTo Slew Rate - 400GTO and 600EGTO with 19.8:1 gearbox||600x, 900x and 1200x ( top speed - 5 degrees per second)|
|GTO Keypad Controller, Version 4.12 (03-07-08) - PDF document|
|GTO Keypad Controller, Version 4.17 Addendum to the v.4.12 Manual - Includes the complete Revised GTO Quick Star Drift Method for Polar Alignment Instructions and a handy one-page Quick Reference Sheet (06-01-10) - PDF document|
The Keypad is included with all GTO mount purchases. If you wish to purchase an extra Keypad as a backup, click here.
Keypad Protector (KEYPRO)
The KEYPRO Keypad protector (shown in the keypad photo above) is a heavy-duty molded rubber casing with a full 1/4" thickness on all impact surfaces. If you accidentally drop your Keypad, the rubber casing will absorb much of the blow. Your display, Keypad, electronics and the case itself will be protected from damage. In addition, the rubber prevents the keypad from sliding when placed on a table or other flat surface and the Keypad will feel secure in your hands as you observe. The KEYPRO also offers protection during transport and storage.
The black case is designed with cutouts for the cable and retractable hanger.
The Keypad Protector is now included with all mounts and Keypads, however it can be purchased separately here, if you need one.
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Inc. - All Rights Reserved
This page was last modified: September 18, 2014
11250 Forest Hills Road, Machesney Park, IL 61115, U.S.A.
Phone: 815-282-1513 Fax: 815-282-9847