Have you any updates on this?
I am finally in the process of building up my AP rig with same mount. I just finished updating the FW on the hand controller. Now I want to do the mount since the FW release notes seems to be a significant update. I have not actually tried yet and just sent an email to SW Support about the lack of instructions. I was thinking of updating via to HC or maybe direct to the USB on the controller box but don't want to risk a screw-up.
I came across your post while doing a google on this subject. I haven't looked for older instructions yet. Will wait to get a response from SW.
[edit #1] - SW responded about 8 minutes after me posting here. That's good customer feedback! However the reply was for the SynScan firmware update how-to & files. So I've replied back to explain I'm looking for the motor control method.
[edit #2] - I notice there's a "SynScan Relay v4" file that can be loaded onto the hand controller. This allows firmware update to the motor controller from the handset. I have not tried yet but this might be the way to do it. Still waiting for additional response from support.
[edit #3] - Well curiosity got the better of me so I decided to go ahead with the experiment. There has been no further response from support at this time. Updated the HC with the Relay firmware (it overwrites the real HC firmware) and connected the HC to the main motor control box which removed from the mount and brought over to my desktop computer. I connected the USB to the HC once the MC box was powered on then ran the MC Firmware Loader and it at applied the v0315 MC Firmware without issue. Once done and powered off I reloaded the HC firmware back to the handset to overwrite the Relay firmware. Yeesh! Based on the GUI of the MC Firmware Loader v176 it looks like it can be done without the handset/Relay. The Com port info is greyed out if the hand controller is connected so that may mean if the handset was not connected it would detect the USB from computer to SynScan box. I'll save that test for another day. I confirmed the HC/MC Firmware Info on the handset once everything was connected up to the mount again and it is updated with the latest version #'s.
[edit #4] I ended up getting another response from support later in the day and they were still on insisting to provide me with the SynScan HC Firmware Loader documentation which of course I didn't need. Two more replies and later support at last sent me the correct PDF for the MC Firmware Loader! The support person stated that they will follow up with the engineers to include this instruction manual with the downloadable zip file on their site. Looking at the single page instructions it is different than what I attempted prior (edit #3) but seems to yield the same result. It doesn't require the 'Relay' firmware and everything is still done via HC in 'PC Direct Mode'. I'll try this later when/if a new FW becomes available. On an interesting note, the link to their help channel in the support email goes to Celestron's support site https://celestron.kayako.com. After a google I see that Celestron & SW are under the same parent company Synta Technology Corporation (Taiwan). I was not aware of this until now.
Well, hope this is helpful to other EQM-35 Pro owners. Instructions may be similar for other models that use SynScan HC/MC in their lineup.
Edited by Signal2Noise, 03 November 2021 - 11:48 AM.