Pin out for DB9-RJ45 connector for Optec to Moonlite

[tooth_dr]

Bit of a niche one, but cant seem to find the information online.

I have a spare Optec FocusLynx Controller that I have read can be used to control a Moonlite focuser.  It requires a conversion cable to go from the DB9 on the Moonlite motor to the RJ45 on the Optec controller.  In the Optec box I have found a cable that goes from RJ45 to DB9 but no labelling etc some I am reluctant to just connect it up to try it.  There is a conversion part for sale but would anyone have information of the correct pinout sequence so I can check the cable I have?

Cheers!

Adam.

[symmetal]

I think you'll find this useful Adam. 🙂

https://optec.us/resources/documents/FocusLynx/19698-FocusLynx_Robo-Focus_Converter.pdf

Alan

[tooth_dr]

51 minutes ago, symmetal said:

I think you'll find this useful Adam. 🙂

https://optec.us/resources/documents/FocusLynx/19698-FocusLynx_Robo-Focus_Converter.pdf

Alan

Alan you are a legend, cheers  🍻

[symmetal]

I forgot to say that there's no standard on the colours used internally in these adapters, and it depends on the manufacturer, so if it has loose flying pins and the DB9 is unwired, it's best to check visually or use a multimeter to confirm what RJ45 pin each colour goes to.

Alan

Edited October 2, 2023 by symmetal

[tooth_dr]

56 minutes ago, symmetal said:

I forgot to say that there's no standard on the colours used internally in these adapters, and it depends on the manufacturer, so if it has loose flying pins and the DB9 is unwired, it's best to check visually or use a multimeter to confirm what RJ45 pin each colour goes to.

Alan

It’s a manufactured cable so I’m just going to be testing what goes where 👌🏻

[pmlogg]

I did something similar to allow control of a Lakeside focus motor with an Optec FocusLynx.  I used a multi-meter as suggested and the combination works fine.  Jeff at Optec is super helpful if you have questions.

[tooth_dr]

Cable I had wasn’t even an RJ45 😂 it was an RJ11.

Ordered this, £4.08 on Amazon

 

@pmlogg I’ve found them helpful too. Even remotely logged into my pc when a firmware update on a focus Lynx controll failed to try and fix it. 

[pmlogg]

That's the sort of adapter I used for my Lakeside connection, but with a male DB9 end.   One thing I found with that was that the pins had a tendency to be pushed back when connected to the female DB9.  I ended up super gluing them into position.

[tooth_dr]

32 minutes ago, pmlogg said:

That's the sort of adapter I used for my Lakeside connection, but with a male DB9 end.   One thing I found with that was that the pins had a tendency to be pushed back when connected to the female DB9.  I ended up super gluing them into position.

That’s a good tip, cheers!

[symmetal]

When inserting the pins they should click into position when pushed far enough in, and you shouldn't be able to pull them back out. There should be little flanges on the pins which spring out when fully inserted to prevent removal. If they don't stay in you can bend the flanges out slightly and try again.

The pins should be free to float around in the socket to ensure proper mating with the male pins when connected. Glueing them in position may hinder this proper mating. 🙂

Alan

[pmlogg]

With mine it was the adapter version with push in male pins.  They didn't lock into position which is why I glued them. 

The adapter may have been from a different manufacturer.  Perhaps I was just lucky they aligned but I did make sure they looked correct before the glue set.

Anyway it's been fine since I glued it. 

[symmetal]

2 hours ago, pmlogg said:

With mine it was the adapter version with push in male pins.  They didn't lock into position which is why I glued them. 

Yes, The male pins are fixed in position by the D9 housing anyway so glueing them wouldn't be a problem. It's the female pins that need to be free to move around a little in the housing. 🙂

Alan

[tooth_dr]

@symmetal hi Alan. I’m going to try this later on. It only requires 4 wires connected, should I just tape the other wires up and leave loose in the housing or would it do any harm connecting them to the DB9 plug?

[symmetal]

As you won't need any of the other wires I would cut them off and heatshrink or tape the individual cut ends so they can't short to anything. If you want to heatshrink or tape the individual unused pins that would be fine too. Connected to the FocusLynx it won't actually matter as they are not connected in the RJ45 but some moonlite/robofocus compatible drivers may supply +12V on one or more of the unused pins, in order that unipolar steppers can be used as well as the bipolar ones you have.

Connecting them to unused pins in the D9 would work with the FocusLynx but could be a bit dodgy if used with a different driver module as above.

The Lakeside steppers are wired with +12V going to D9 pin 5. The Lakeside motors themselves can be wired as unipolar or bipolar. Disconnecting and isolating the 2 motor wires to pin 5 turns the stepper into a bipolar one which is moonlite compatible, which is how I use it with my arduino based homemade bipolar drivers. 🙂

Alan

Edited October 8, 2023 by symmetal

[tooth_dr]

Hey Alan @symmetal

Thanks again for the instructions, have it all connected and working successfully 👍

I have another small problem that maybe you could help me with please!  I went to connect up the temp sensor, because the moonlite doesnt have an inbuild sensor (unlike the Starlight HSM motors).  The temp sensor goes inline between the hub and the focuser.  Problem is that the input connector for the focuser has only 6 pins and the 8 pin plug doesnt fit.  The connector from the other side of the temp sensor to the hub is 8 pin and a normal ethernet cable.

I just spoke to Jeff at Optec and he says its will work, I just need to convert the cable to a 6 pin (RJ12) plug.  He attached the pinout on an email, I've attached it below.  Would you be able to help me with the correct way to wire from an 8pin on the DB9-RJ45 adapter to a 6 pin on the temp sensor (if you dont mind).

 

19539_External_Temp_Probe_Rev1.pdf

[symmetal]

Hi Adam,

In your original post you were looking for the pinout of the adapter you had in your Optec box which you thought was RJ45 to DB9 but turned out to be an RJ11 to DB9. Is it actually an RJ12. They are both the same physical connector but the RJ12 has all six pins installed while the RJ11 only has the centre four pins with the outer pins blank.

Is this perhaps the adapter that works plugged into the temp probe box using an RJ12 to RJ12 cable to connect to the DB9 focuser?

The thing that confuses me though, is that the pins used for the focus motor in the RJ45 pinout on the temp probe adapter, is different from the focus motor pins of the RJ45 adapter you newly wired. If the temp probe adapter is to be placed between the controller and the focus motor shouldn't the RJ45 pinout be the same as far as the motor pins are concerned. Or is the RJ45 on the newly wired adapter connected to a different RJ45 port on the controller. 🤔

Personally, instead of an RJ12 to DB9 adapter, if I didn't have one, I would just get an RJ12 to RJ12 phone cable which are cheap, cut off one end and solder a DB9 connector in its place to connect to the focuser.

Alan

Edited October 17, 2023 by symmetal

[tooth_dr]

Sorry for the confusion Alan.
The original DB9 to RJ45 is correct and is the way conversion cables are supplied.  It is RJ45 on the Optec box and it uses a red straight through ethernet cable to connect to my Starlight HSM motors.  With the Moonlite focuser it uses a normal Ethernet cable (crossed over wires inside) from the hub and into the DB9 adapter. 

The temp sensor was an afterthought. I assumed the temp sensor would be RJ45 on both sides, to me that would have been logical.  And I thought I’d just add it into the set up by plugging a Ethernet cable into both sides of it. Thinking about it now, the wiring on that latest diagram will be a for a straight through red Ethernet cable going from the optec hub to the temp sensor, as this is the type of cable they supply with their kits.

I’m thinking I can make an RJ45-RJ11/12 cable to match pin out from latest diagram to go from focuser to temperature sensor, and use a red straight through Ethernet cable from the optec hub to the temperature sensor.

I’m sorry this is very confusing 

Edited October 17, 2023 by tooth_dr

[tooth_dr]

40 minutes ago, symmetal said:

I would just get an RJ12 to RJ12 phone cable which are cheap, cut off one end and solder a DB9 connector in its place to connect to the focuser.

This seems like a very good solution TBH, I'll get one of them ordered.

[symmetal]

10 minutes ago, tooth_dr said:

This seems like a very good solution TBH, I'll get one of them ordered.

Just check it's RJ12 (6P6C) in its spec similar to this, as a 'standard' phone extension cable may be RJ11 (6P4C). 

Alan

[tooth_dr]

39 minutes ago, symmetal said:

Just check it's RJ12 (6P6C) in its spec similar to this, as a 'standard' phone extension cable may be RJ11 (6P4C). 

Alan

I have the cables at home, my late father worked for BT so I've plenty of bit and bobs knocking around.  I will need to order a DB9 connector.

[symmetal]

You can get these solderless DB9 connectors, but soldered would be preferable if you're well trained 😁, as it's one less connection in the chain.

Alan

[tooth_dr]

Oh aye soldering is ok. I modified a toucam back in the day, and continue to this day to footer about with stuff!  What would be the correct pin order?

[symmetal]

The pin numbering of RJ11 and RJ12 connectors is a bit of a minefield, as the plug pin numbers are the reverse of the socket numbers. 😬 If you look on the internet you'll find both number orders applying to the plugs as some people took the socket numbers and assumed that was the same as the plug, and vice-versa which would seem logical.

I would take the lid off your temperature probe adapter and see which 4 pins of the RJ12 socket are actually wired and then see what colours on the cable they correspond to when your RJ12 cable is plugged in.  Using the RJ12 pin connection from the diagram, rather than it's pin number which may be wrong, here's what your adapter cable should be like.

RJ12 Coil 2B to DB9 pin 1

RJ12 Coil 2A to DB9 pin 2

RJ12 Coil 1B to DB9 pin 3

RJ12 Coil 1A to DB9 pin 4

It's not critical if you get the wiring incorrect. The worst that will happen is the stepper won't move at all, (as the coils will effectively be open circuit), or it turns in the wrong direction if any one of the coil pairs is reversed. If both coil pairs are reversed it will work as normal. 😉

Alan

Edited October 17, 2023 by symmetal

[tooth_dr]

Hi Alan

I had a rummage and found a cable which is RJ12 to DB9!  Don’t know if it’s wired correctly though.

I’ve attached photos and tested for continuity in the circuit.  Hopefully this makes sense to you.

DB9 to RJ12 cable:

Inside DB9 connector:

RJ12 plug

Wiring of DB9 to RJ12

How RJ12 fits into temp hub:

Wiring continuity through PCB:

[tooth_dr]

If I’ve got this right, I should desolder the DB9 connector wiring, and reconnect as follows:

Pin 1 : yellow 

Pin 2 : green

Pin 3 : brown

Pin 4 : white