8 replies to this topic

[Hippinse]

I have recently been given a fairly old CGEPro mount which works fine with the nexstar+ handset.

I would like to set it up to connect to my laptop so I can control it from the computer. The mount has an RJ45 port labelled as PC, and I have a Lynx astro usb to rj45 rs232 serial port adapter which I use successfully with my Skywatcher HEQ5pro.  (photos attached)

 

The laptop detects the serial port as com4. (photo attached)

 

However when I connect the cable to the mount and power it on none of the software installed on the laptop can detect a mount on com 4 (or any other com port).  This includes:
1. CPWI

2. Nexremote

3. NINA

4. EQASCOM

 

I have scoured the Celestron support pages and the online PDF manual for the mount, but the only references I can find to connecting to a PC suggest connecting through the handset, and make no mention of the PC port...

 

Any answers (and supporting details) to the following questions would be appreciated!

 

1. Does the PC port provide connection for computer control (if not, what is it there for)?

2. Have Celestron used a non-standard implementation of of the RS-232 wiring, requiring a different cable?

3. Do I have to connect via the handset (which has an rj9 connector in the base of it) also requiring a different cable?
4. I also have an RJ11 to serial port adapter which would fit the same connector as the handset, should I be using that instead of the rj45 pc port?

 

 

 

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[freestar8n]

I think you need to install the prolific serial driver.  I had the same problem recently setting cpwi up on a new mele computer.  I was able to find the driver download on the web.

 

Others may have more info - but it fixed it for me.  Not sure why the driver isn't part of the installation or something.

 

Frank

[mclewis1]

Your RJ45 to rs232 serial cable is likely incorrect. You'll need the Celestron specific cable which has a very unique pinout. It's model #93922 (but no longer sold - but there are some 3rd party versions floating around), and the pinouts for the adapter portion are in the scope manual or on Mike Swanson's website ... www.nexstarsite.com

 

The Celestron cable is a 2 part setup, one is a standard Ethernet patch cable and the other part is the serial DB9 to RJ45 adapter with the unique pinouts.

 

The PC port on the Celestron mount is a full rs232 interface that includes hardware RTS/CTS lines.

[mlord]

The PC-Port on the CGEpro is for use only with some obsolete software called NexRemote.  For whatever reason, known only to Celestron, it does not work with anything else (even though it could..).

[rutherfordt]

Yes, as mlord just mentioned, you hook a computer up to the CGE Pro through the port on the underside of the hand controller, not one of the ports on the mount pier itself.  The hand controller will have either a telephone-type socket on the underside or a usb-- depends on how old it actually is.  A lot of mount manufacturers in those days set up their mounts to be controlled through the hand controller-- not just Celestron.

 

Tom

[mclewis1]

If the OP gets the correct cabling for the PC Port then NexRemote will work to control the mount (it will be the hand controller) and then via the serial pass through capability (via both NexRemote and the device driver for the com port) just about any other Windows based scope control app can be run to control to the mount. The exception would be another app such as CPWI that also wants to be the hand controller ... but any of the other Celestron compatible scope control apps with or without ASCOM support should be fine.

 

I thought (but dangerous to rely on just my memory) that CPWI had been upgraded to handle the on mount USB (internally a serial connection) on the CGX mounts and then later also the older serial only PC Port that exists on the CGE/CGE Pro/NS GPS and CPC mounts. Going through the limited release notes I don't see a direct reference to the PC Port but there were a few discussions on CN about this. One other area of discussion was whether or not Mlord's DIY homebrew adapter could also "fake out" the various apps so they would work through the PC Port (something about the correct initial response from the MC board via the PC Port). What I can't find is whether or not anyone ever got around to actually testing this capability against the various MC firmware levels.

 

Going back to the other form of connectivity with the Celestron mounts - The connectivity via the little 4 pin RJ9/22 connector on the bottom of the hand controllers also requires a specific serial cable (or equivalent pinouts on a different wiring setup). There are issues with other equally simple looking serial cables ... for example the Meade serial cable does not work on the Celestron hand controllers so I believe that the OP's other RJ serial cables are likely a problem. The correct cable for the old hand controller serial connection is the #93920 (RJ9 to DB9). And remember that you'll still need a USB to rs232 serial adapter.

Edited by mclewis1, 22 April 2025 - 09:36 AM.

[mlord]

As I recall, the "PC-Port" on that mount simply uses a different baud rate than what CPWI expects, which is why if fails with CPWI.  Dumb.

 

The HBG3's own USB port can be used for mount control from CPWI though.

 

I think there are mounts with built-in USB, and I do recall people using those with CPWI.  The USB port on the Celestron Focus Motor also works, as does the one on the 2X/4X Dew Controller.

[Hippinse]

Thanks everyone, how frustrating to go to the effort of putting a connection in place then rendering it useless with dodgy pinning / software...

Anyway, having  read through the responses here I have concluded that none of the cables I currently have are compatible so I have ordered a USB (with rs-232 adapter chip built in) to RJ9 cable to connect to the handset, hopefully that will see me right, I'm not fussy about which software I end up using, just as long as something will connect to it!

[mclewis1]

Just make sure whatever cable you buy (or make) is specifically for a Celestron mount, don't assume compatibilty just because of the type of connections used. There are no standards for the pinouts of the various RJ connectors and it seems that just about every scope manufacturer has used something different.