SkyWalker1's specifications


Size (excluding connectors):

5.08" x 3.29" x 1.15" (129.0mm x 83.5mm x 29.2mm)

Control switches:

Power
System/SkyWalker-mode select

Indicators:

Power
Programmable Mechanical Error Correction (PMEC)
Battery status
Operational status (System/SkyWalker-mode and "Celestial Sync")

Internal Time-base Accuracy:

+/-30ppm from -20C to 50C ambient

Power Supply (2.5mm connector):

10.8VDC to 14.2VDC*
100mA with handpaddle only and no accessories attached to the HighDrive or TCS Ports.
2.75Amps with HighDrive & TCS ports all at maximum load.

Environmental Requirements:

-20C to 50C ambient
5% - 95% relative humidity, non-condensing

Motor Ports (two MJ-12):

Motors
  - Step and Dir control signaling via 20mA current loops to external motor drivers.
  - 160,000 steps/second maximum.
Limit switches
  - Normally closed contacts which open to disable motors when mount/scope move beyond safe limits.
Index inputs for Periodic Error Correction for each axis
  - Optional normally open contacts to indicate one complete rotation of worm gear.
  - Required for Periodic Error Correction programming to be available at power-up of SkyWalker1 without retraining.

HighDrive Port (8 pin MiniDIN):

2 BiDrive outputs each capable of sourcing or sinking 250mA from each other in a push-pull configuration.
  - Powered by 12VDC input power supply voltage or internal 9VDC** regulator (ideal for motorized focusers).
4 UniDrive outputs each capable of sinking 500mA. The 4 UniDrive outputs are limited to a total draw of 1.0Amp.
  - Powered by 12VDC input power supply voltage or internal 9VDC** regulator.

Telescope Control System (TCS) Port (6 pin MiniDIN):

Expansion port for future Astrometric Instruments' accessories.

Autoguider inputs (MJ-12):

Connects to an autoguider such as the SBIG ST-4.
The autoguider corrects at the currently selected SkyWalker1 pan/correction rate.

Axial Encoder inputs (MJ-45, used in System mode):

Connects optional optical encoders for closed loop operation.
  - Supports standard quadrature-output encoders.
  - Supports Tangent Instruments™ pin-out and Astrometric Instrument's enhanced encoder pin-out (i.e. provides axial index input for alignment from indices).
Detects up to 20,000 encoder quadrature transitions per second.

Handpaddle port:

MJ45 (8 wire) HP1 and SkyGuide "smart handpaddle" compatible.

PC Comm port (MJ-11, used in System Mode):

Three wire RS-232 interface (Txd, Rxd and GND)
9600 Baud, 1 Stop bit, No Parity
50 ft. (15m) maximum

HP1 handpaddle:

Included with SkyWalker1 purchase
14 ft (3m) coiled cord
Powered from SkyWalker1
3.60" x 5.75" x 1.20" (92mm x 146mm x 31mm) excluding cord


*  When BiDrive outputs are powered at 12VDC, the input voltage specification changes to
12VDC +/-10%.

** Total current from the internal 9V regulator can not exceed 500mA.

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