In order to use the EQMOD software with your mount you will need:
Included in the EQASCOM distributable is a telescope simulator that allows you to evaluate the EQMOD applications without needing a connection to a real mount. In order to use the EQMOD Simulator you only need:

Mount Types Supported:

RA Gear Teeth RA Gear Ratio Microsteps per RA Revolution Microsteps per Worm Revolution Resolution (arcsecs) MicroSteps
Skywatcher / Orion
EQ3-2 + Synscan Upgrade Kit 130 715:1 4576000 35200 0.283217 32
NEQ3/HEQ3 Synscan130715:14576000352000.28321732
SkyView Pro + Synscan Upgrade Kit144704:1450560031288.890.28764232
SkyView Pro EQ144704:1450560031288.890.28764232
EQ4 + Synscan Upgarde Kit (EQ5) 144 704:1 4505600 31288.89 0.287642 32
EQ5 + Synscan Upgrade Kit 144 704:1 4505600 31288.89 0.287642 32
EQ5 Synscan144705:1450560031288.890.28764232
HEQ5 + Synscan Upgrade Kit135705:1902400066844.440.14361764
HEQ5 Syntrek 135705:1902400066844.440.14361764
HEQ5 Synscan (Orion Sirius)135705:1902400066844.440.14361764
EQ6 +Synscan Upgrade Kit
EQ6Pro Syntrek 180705:1902400050133.330.14361764
EQ6Pro Synscan (Orrion Atlas) 180 705:1 9024000 50133.33 0.143617 64
NEQ6 180 705:1 9024000 50133.33 0.143617 64
AZ-EQ6GT  (Orion Atla Pro AZ/EQ-G)180720:19216000512000.14062564
AZ-EQ5GT  (Orion Sirius Pro AZ/EQ-G)135405:1 5184000 384000.2564
EQ8 (Orion HDX110 EQ-G)435435:111136000256000.11637964
Avalon Instruments
M-Uno Fast Reverse Single Fork Arm EQ180705:1902400050133.330.14361764
Linear Fast Reverse EQ180705:1902400050133.330.14361764

Vixen GPDX fitted with Synscan Upgrade Kit (EQ5)144704:1450560031288.890.28764232
Vixen SP fitted with Sysncan Upgrade kit (EQ5)144704:1450560031288.890.28764232

Note: The Orion Atlas EQ-G is the same mount as the EQ6 Pro, the Orion Sirius EQ-G the same as the HEQ5. In different countries the branding/ designations of these mounts may vary slightly - If in any doubt please consult the EQMOD Yahoo group for advice.

For the AZ-EQ5GT mount:
Total Steps: 5184000
Worm Steps: 384000
Tracking Offset:0
  • To use the internal USB port set the EQASCOM communications baud rate to 115200bps via the EQASCOM setup screen.

Other Mount Types:
Mount types other than those listed above may be made suitable for EQASCOM support either by:
  • fitting a synscan upgrade kit to your mount.
  • building your own EQASCOM compatible mount controller (see the AstroEQ project by Tom Carpenter for an example of how this can be achieved).
  • modifiying the EQASCOM source to interface with your mount's goto controller.

Mount Interface:
EQMOD talks to the mount by issuing comands to a serial port.  This may be an 'on-board' RS232 port, or a virtual port associated to a external USB serial adapter or Bluetooth interface. The mount itself does not accept RS-232 level signals and so a piece of hardware (EQDirect) is required to convert the output of the serial port to TTL levels. There are a number of options available to achieve this.

  • V3 SynScan "PC Direct" 
This handset feature was introduced with SynScan firmware release V3.21 and became stable by V3.25. It provides a communication path such that PC messages recieved by the synscan handcontroller are forwarded to the mount. Despite its inclusion PC-Direct mode remains an undocumented feature of the Synscan handcontroller and the EQMOD developers have no knowledge of how it works or of its limitations. We cannot therefore make any guarentees as to its operation with EQMOD which was designed only for direct connection to the mount. Whilst PC-Direct mode offers an ideal method for users to evaluate EQMOD control we would advise that for extended and/or unattended use one of the options below is adopted.
Mount interface units are quite simple to build for yourself if you have basic soldering experience.
For those not confident in building their own, or who prefer the peace of mind of purhasing a ready made tested unit, RS232, USB and Bluetooth EQDIRECT units (often named EQDIRs) are offered by several vendors worldwide.
If you have an older Version 2 Synscan handcontroller then it is posible to modifiy it to provide a direct mount interface. Most folks would not go down this route though and would instead either build or purchase an EQDIRECT.

Interface TypeProsCons
EQDirect-232Long Cable Run
shortest comms latency (16mS transaction time)
PCs/Laptops may not provide inbuilt RS-232 port and so an additional USB/Serial adapter may be required. The EQMOD Yahoo group contains a list of USB to Serial convertors that are suitable for interfacing to RS232 type EQDIRECT interfaces.
EQDirect-USBStandard Interface for PC/Laptops
Easy to Self Build
Shortest comms latency (16ms transaction time - may increase if using ethernet extenders)
5m max cable lenght without USB repeater/hub/active cable/ethernet extender.
Potential for USB power/bandwidth issues if sharing with other USB devices  - Powered USB hub recomended.
EQDirect-BTNo wires!Longer comms latency (50mS transaction time)
PC-DirectEQDirect device not required - uses standard synscan handcontroller PE interface cable (firmware update cable).Longer comms latency (32mS transaction time); Undocumented handset feature - EQASCOM has not been specifically designed to us this interface.
Synscan firmware updates may affect operation.

The cabling between the USB-RS232 convertor / PC and the EQDirect should be a 'straight' RS232 cable. The Cabling between the EQDirect and Mount should be a 'straight' cable but the connector type may vary with different mount types.

TTL signaling is basically a circuit board level interface and is not intended for covering long distances so keep the connection form the EQDirect device to the mount short (a guide to the maximum length would be the length of the synscan-mount cable though we would recommend the shorter the better).

If using a USB EQDIRECT device the usb cable is limited to 5m .For longer lengths you either need an "active cable" or a hub (powered).

If you need to cover longer distances then use a USB-232 convertor at the PC but make sure it is a good one that suppies true +-9V RS232 signals - these are typically the more expensive types. Run a standard shielded RS232 cable to the mount and fit an EQDIRECT (232-TTL convertor) at the far end. As before keep the distance from the EQDirect to the mount short. RS232 should be good for up to 30 metres.

If you want to control the mount whilst at the eypiece, or when away from the PC a mount controller will be required. EQMOD allows numeric keypads, mice and game controllers to be used for this function. Also, by using third party software it can be possible to configure other devices, such as Wii controllers for this purpose (consult the EQMOD Yahoo group for details on this). Generally most people find a wireless/wired gamepad an ideal mount controller.

Optional Extras:
Depending on your setup and individual requirements you may wish to consider:
  • GPS device with serial/USB interface. The EQMOD Yahoo group contains a list of compatible devices.
  • Planetarium Software that supports the ASCOM telescope interface. Cartes du Ciel is highly recomended as a starting point.