Exstension cable between PC and Synscan Hand control

[Al-man]

Can a Cat5 cable with suitable adapters each end be used to connect a PC to the Synscan hand control over a distance of 25 mtrs ? . I would like to control the scope sited in the garden from inside the house and wondered if this would work. I have been using Sky Safari with SkiFi but found when using the direction arrows on my Ipad, scope control can be quite poor (even when stood beside the mount). I have been trying Stellarium with Stellarium Scope and EQMod  with short cables which works well, so would like to try over a longer distance, but not sure which type of connection would be best.

Thanks in advance for any advice.

Alan

[Merlin66]

I use a Cat5 cable to the Syscan but only a 5 mtr length. Should work over longer distances.

 

[symmetal]

As it's just RS-232 data going over the cable (very slow bit-rate compared to USB etc.) it should work at over 100m I would have thought.

Alan

[Merlin66]

Alan,

you don’t need any other adaptors, the Cat 5 fits directly between the Synscan and the mount.

 

[Dr_Ju_ju]

The one thing that may cause an issue, as the controller is normally powered via the mount, is if there is any voltage drop along the cable, making it unreliable.

The easy solution, is to use a 'local' power supply (12v).

[stash_old]

8 hours ago, Merlin66 said:

Alan,

you don’t need any other adaptors, the Cat 5 fits directly between the Synscan and the mount.

 

Needs qualifying slightly - a straight thru cat 5/6 cable is ok but do not buy a standard Ethernet cable as this has pins crossed (i.e. its not pin to pin). 

Std max on rs232 cabling (without boosters) is 50 feet . However the Handset to mount is TTL levels (5v/3.3v) not the much higher voltage levels used in Std RS232 so as Julian has said voltage drops could cause problems - not recommended for long distances IMHO but hell try it if it works for you !!!! ?

The output from the handset is RS232 hence the need for a USB/Serial adapter and therefore you should be able to run the USB side up to 20m+ using a (or a couple) decent active repeater cable. But that would mean that the handset would not be within your home at a guess ?

There are other solutions - Serial WiFi,Synscan App etc which are well documented else where on this site .

 

 

[Merlin66]

Hmmmm

I’m currently using the Synscan with my HEQ5 using just a Cat5 cable over a 5 mtr distance. No converters, no adaptors, just the cable . Works for me, no issues, no drama.

[Al-man]

Perhaps I should clarify what I want to do, which is leaving the handset with the mount and connect from the PC to the Synscan handset via a long Cat5 cable. This would be instead of using WiFi which I found unreliable. So if I am right in thinking that it's just data running through the cable to the Synscan handset from the PC, can I use a Cat5 cable with a RJ45 to RS232 adapter one end and a RJ45 to USB adapter the other end.

I am already using USB3 active extension cables along with a powered USB3 hub to connect to my ZWO ASI120 MC-S camera, but am hoping that using a Cat5 cable for linking the PC to handset would be a simpler and much cheaper option.

Another question ? Is there a device to remotely focus the telescope, or would that be even possible on my Sky-Watcher 150PL telescope ?.

[Merlin66]

Ahhhh, I actually keep the Synscan inside with me and have the cable (Cat 5) connecting it to the mount.......

Re focusing I use a SW electronic motor to run the focuser again with a 5 mtr cable from inside (this is my solar imaging set-up)

 

[stash_old]

3 hours ago, Al-man said:

This would be instead of using WiFi which I found unreliable

You dont have to use WiFi at all if you check the EQMOD site out you can you HW VSP or this https://www.hw-group.com/software/hw-vsp3-virtual-serial-port - there must be an Apple version surely unless you are running Windows emulator?

This creates a virtual COM port so you can connect CDC or whatever but then will transmit over Ethernet (RJ45 cabling 100m no problem) to a RPI2,RPI3 via the wired Lan port which is converted to the USB/Serial adapter (you use this already  just needs plugging into RPI USB port !)  via a piece of software called Ser2net (been around for 20yrs).

A little more complicated than Cat5 extension I grant you but later you can add something like Robert Browns excellent Focus controller over the same cable by just changing a few parameters and adding a new usb/serial adapter for the focuser.  No WiFi involved!!!!

Whatever you do good luck !

 

[symmetal]

The maximum recommended cable length for RS-232 is 50 ft at 19200 baud, at the 9600 baud used by the Synscan to PC connection it's 500 ft so you have no problems there. You just need to connect the RJ12 connector on the Synscan to your USB to 9-pin Serial adaptor on your PC (assuming it's a relatively modern PC you don't have an actual serial port). You should have the RJ12 to 9 pin serial cable that came with your Synscan (about 2m long) so you need a 25m D9 male to D9 female cable to connect the two. These were plentiful to buy 10 years ago but are scarce nowadays.

The easiest way out is to get two D9 to Cat5 adapters like these  one male D9 and one female D9 and use the 25m Cat5 cable to connect them. You have to push the pins into the D9s yourself though you might be able to get some made up. You only need three of the pins on the D9s wired (2, 3 and 5) wired but you might as well push all the wires in, wiring 1 to 1, 2 to 2 etc. leaving out pin 9. Just ensure the colours match on the wired Cat5 sockets so you don't end up with crossed wires.

Alan

Edit... Reading your latest post you actually want to send the Camera data down the Cat5 too so ignore all I've put.   ...backs slowly towards door...

[Al-man]

59 minutes ago, symmetal said:

The easiest way out is to get two D9 to Cat5 adapters like these  one male D9 and one female D9 and use the 25m Cat5 cable to connect them. You have to push the pins into the D9s yourself though you might be able to get some made up. You only need three of the pins on the D9s wired (2, 3 and 5) wired but you might as well push all the wires in, wiring 1 to 1, 2 to 2 etc. leaving out pin 9. Just ensure the colours match on the wired Cat5 sockets so you don't end up with crossed wires.

Alan

Edit... Reading your latest post you actually want to send the Camera data down the Cat5 too so ignore all I've put.   ...backs slowly towards door...

This is the setup I was thinking of and have seen the Cat5 RJ45  to DB9 female adapters already made up but none for DB9 male, so I guess I will have a go at connecting them up myself. It can't be that difficult can it ? ,

I won't be connecting the camera via Cat5  though as it seems to work fine via the USB cables, so thanks for your advice.

Alan

[symmetal]

1 hour ago, Al-man said:

This is the setup I was thinking of and have seen the Cat5 RJ45  to DB9 female adapters already made up but none for DB9 male, so I guess I will have a go at connecting them up myself. It can't be that difficult can it ? ,

I won't be connecting the camera via Cat5  though as it seems to work fine via the USB cables, so thanks for your advice.

Alan

Ah! I misunderstood my misunderstanding.  Glad it was what you wanted. Those DB9 to RJ45 adapters are used for many things and not just RS-232 so are wired up depending on what you want. For some uses, using the Cat5 twisted pairs a certain way may be necessary, but for your application it's not important.

They are easy to wire up. Just push the coloured wire pins into the back of the DB9 until they click, noting the pin numbers on the DB9. If you get the male and female adapters from the same source there is a good chance the wires connected to the RJ45 have matching colours but it's best to check. When you pushed all the pins in just ease the DB9 into the plastic housing until it clicks.

It's worth getting a couple of each adapter as spares, as if you push a pin into the wrong hole by mistake you can't get them out again. 

The ones I linked to are rather expensive, these from kenable are a better buy at £1.90 each.

RJ45 to DB9 Female

RJ45 to DB9 Male

Oh, and ethernet patch cables (the standard ethernet cable you buy) are wired straight through. Ethernet cross-over cables are a special case and are labelled as such. 

Alan