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PC Port---RJ45 Phone or "RJ45" Ethernet Plug

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#1 barbarosa

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Posted 03 November 2013 - 02:25 PM

Do any of you control your CPC from a PC using the PC port on the mount, rather than through an RS233 connection to the hand control? How does it work?

Can I use either an RJ45 plug and flat wire telephony cable or an Ethernet cable and an RJ45 /DB9 adapter to connect to the RS232/USB adpapter that I use with the hand control?

Thanks.

#2 mclewis1

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Posted 03 November 2013 - 03:16 PM

David,

What are you trying to do?

RJ45 is an 8 pin connector (not 6 pins like the more popular RJ11/12 with flat wiring). The RJ45 connectors are normally seen on Ethernet patch cables, it's not usually used in any telephony cabling. There is however also flat Ethernet cabling.

The PC port is indeed an 8 pin RJ45, the cabling from that is usually a regular Ethernet patch cable that has an RJ45 to DB9 serial adapter on one end. That RJ45 to DB9 adapter has the required wiring within it (the cable is not wired one to one through to the DB9). The DB9 side is then usually connected to a serial to USB adapter.

If you have a serial to USB adapter that has an RJ45 connector on it (never personally seen that) you'll still likely need to swap some wires around.

The PC port cable and adapter are available as Celestron product #93922 or you can wire up your own, the pinouts for doing that are on http://www.nexstarsi...ammingCable.htm Generic versions of the RJ45 to DB9 adapter are available from quite a few online sources, they usually have push in wiring inside them so you can do your own custom wiring quite easily (and no need to cut and solder stuff).

#3 barbarosa

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Posted 03 November 2013 - 04:30 PM

Mark, before I read your response I amended my post to try to clarify my intent. Let me start again.

Currently, I connect a PC to the CPC, via a USB/serial adapter and the Celestron cable plugged into the hand control. Out of habit I guess, I do the alignment with the hand control rather than Nexremote, and use Stellarium to control go-to.

What I want to do is connect to the PC port rather than the hand control and run the whole setup from a PC using Nexremote. The PC port would simplify cable management.

I have a DB9 adapter alleged to be correctly for use with the PC port. Today I used it, a short length of CAT 5 and a serial/USB adapter to connect the mount to a PC.

Nexremote appears to see the mount. The Celestron MC Update software appears to see the mount (it can read the installed firmware version). However, pressing an arrow key in Nexremote does not cause movement. Slewing to an object with Nexremote gets an "aborted" message.

As to terminology, I am still a tyro, one who was lectured some years back by a POTS person on misuse of the RJ term by IT people. I was using a desk in IT that week and really had no clue about Ethernet or Token Ring or any of that stuff, but I got the message. :tonofbricks:

They look the same to me, but wiki says,

Although commonly referred to as an "RJ45" in the context of Ethernet and category 5 cables, it is incorrect to refer to a generic 8P8C connector as an RJ45.[7][8][9] A telephone-system-standard RJ45 plug has a key which excludes insertion in an un-keyed 8P8C socket.[10] The registered jack (RJ) standard specifies a different mechanical interface and wiring scheme for an RJ45S from TIA/EIA-568-B which is often used for modular connectors used in Ethernet and telephone applications. 8P8C modular plugs and jacks look very similar to the plugs and jacks used for FCC's registered jack RJ45 variants, although the RJ45S is not compatible with 8P8C modular connectors.

#4 A. Viegas

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Posted 03 November 2013 - 05:32 PM

Hi David

I am doing exactly what you are describing. Allow me to elaborate my setup and reasoning. First things first, I use the 'motor control' cable in the CPC PC port. I bought mine here, and its cheap and works great. Astrogadgets

Next. NexRemote and the HC do not work well together so i have the HC unplugged when I am using NexRemote. Ok, so with the usb dongle plugged into the RS232 serial from my astrogadgets cable I fire up NexRemote and tell it which COM port the USB dongle is attached to and it finds my CPC and its off to the races...

** I have an intermediate step here which I use because I do not want to sit outside with the laptop and the telescope... ** -- So I actually have the USB dongle plugged into a USB hub with a long run series of USB 5m repeater cables back to my home office. This allows me to control the telescope from inside using NexRemote. How do I do the alignment you ask? I use this free vnc program called "Teamviewer" which connects from my laptop near the CPC to my home office desktop. The NexRemote software is actually running on the desktop and the laptop wirelessly connects and gives me the actual viewscreen of the desktop so I can do all the alignment, ASPA and what not outside to get setup. When I am done I hibernate and usually dont have to do this routine again.

Hope this helps

Al

P.S. Not sure I answered your question, but I DO NOT use an ethernet CAT4/5 cable. I use the proper Serial cable for the CPC and then a USB dongle to the computer/hub

#5 Stacy

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Posted 03 November 2013 - 09:24 PM

mclewis1 said: RJ45 is an 8 pin connector (not 6 pins like the more popular RJ11/12 with flat wiring). The RJ45 connectors are normally seen on Ethernet patch cables, it's not usually used in any telephony cabling. There is however also flat Ethernet cabling.


FYI: This statement could be misleading. Most modern (digital) phone systems utilize the exact same wiring and connectors that are used for Ethernet. Using something different unnecessarily complicates installation and maintenance. :ubetcha:

#6 barbarosa

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Posted 03 November 2013 - 09:54 PM

Al, you nailed it. My sublime object is to sit indoors on cold nights (and not so cold) or when we want to share with people who question the sanity of sitting in a dark shed.

I have a second PC, a small netbook, and I recently installed found and installed Teamviewer.

I checked the pin out of the RJ45/DB9 adapter that I have. It matches the diagram at the nexstarsite an continuity is OK. I guess I will order a proper cable.

Daisy chained USB does work, even with two or three of the long 10m, 15m and 25m cables from monoprice.com, but I want to try running a serial connection from the mount to the RS232/USB adapter at the PC in the house, using twisted pair and not USB.

Anyway I will get something to work before the cold and damp sets in.

#7 barbarosa

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Posted 03 November 2013 - 09:56 PM

mclewis1 said: RJ45 is an 8 pin connector (not 6 pins like the more popular RJ11/12 with flat wiring). The RJ45 connectors are normally seen on Ethernet patch cables, it's not usually used in any telephony cabling. There is however also flat Ethernet cabling.


FYI: This statement could be misleading. Most modern (digital) phone systems utilize the exact same wiring and connectors that are used for Ethernet. Using something different unnecessarily complicates installation and maintenance. :ubetcha:


I understood tip and ring. :lol:

#8 barbarosa

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Posted 06 November 2013 - 09:15 PM

Update--

I added a couple of RJ45 flat wire "data" cables to a an order from monoprice.com. Set up modular DB9 adapter per the pin out on the Nexstarsite and bingo, it works.

Money saved, over night delivery, the mount spins. :jump: Then the clouds roll in
... :4

#9 herrointment

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Posted 06 November 2013 - 10:15 PM

Cashing out on the trifecta, eh?






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