Help pls, Guiding cables, Do i need to connect the ST4 cable to laptop and mount? #tracking

Jerry Hubbell - Explore Scientific VP Engineering

On Fri, Aug 20, 2021 at 09:12 AM, Euan Milne wrote:
Some resources say no and other say yes. 
Hi Euan,

There are two ways to connect your mount to your guiding system via the universally used PHD2 Guiding software. You can use the legacy ST4 connector on the mount with an ST4 cable to your camera. This is called "On camera" in PHD2. OR, you can eliminate the use of another cable by using the PulseGuiding API in ASCOM by selecting ASCOM in PHD2 for the auto guiding connection. PHD2 makes use of the USB connection you have to your mount already to send pulses to your mount. 

The ASCOM PulseGuide function is the best way to go. No need to use the legacy ST4 connector anymore.
Jerry Hubbell
Vice President of Engineering

Explore Scientific, LLC.
jrh at
1010 S. 48th Street
Springdale, AR 72762

Author: Scientific Astrophotography: How Amateurs Can Generate and Use Professional Imaging Data
             Remote Observatories for Amateur Astronomers: Using High-Powered Telescopes From Home

Mark Slade Remote Observatory (MSRO) IAU MPC W54 Equipment
Wilderness, VA
: ES PMC-Eight G11 + Telescope Drive Master (TDM)
Scopes: ES 165 FPL-53 ED APO CF, ES 102 FCD100 ED APO CF
Cameras:  QHY174M-GPS + FW, QHY163C
Misc: 3-inch 0.7x Focal Reducer Field Flattener, Filters: Luminance,
Red, V-band Photometric, Diffuser, 200 lpmm Spectral Grating

Software: MaxIm DL 6, Cartes du Ciel, Astrometrica, AstroImageJ, AutoStakkert!

Euan Milne


Getting my head around the guiding setup. Cable wise, I have a USB cable from Laptop to Mount, usb Cable from Laptop to Guide Camera, Do I need to use the ST4 cable between the camera and the mount or the laptop and mount or something else?

Some resources say no and other say yes. 

 I plan on using ATP / Stellarium / Phd2 and ASCOM. I have all the software talking to each other.
Mounts: ES PMC-8 IEXOS-100
Scopes: TAL-1
Cameras:  Canon 1200D, Canon 70-210mm,  Tamron 150-600mm, 50mm prime. 
Msc: 12V Powerbank
Software: ExploreStars, SharpCap, All Sky Plate Solver