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View Full Version here: : Meade LXD55 with Southern Stars Skywire


TonyG
20-01-2014, 10:56 AM
Hi all, I need help getting my iPhone connected to my Meade LXD55 mount via Skywire (to run Sky Safari Pro).

I bought the Skywire cable but thought my own DB9-RJ11 4-pin cable I was using to control the Meade from my laptop would do the job. But I cannot get a connection.

The only logical place to plug the RJ11 cable into the LXD55 is the AUX port, although the Skywire manual seems to say not to do this. The 4-pin connector seems loose in that socket - looks like it needs a 6-pin connector, but again the specs online suggest a 4-pin connector for the LXD55.

My setup is DB9-RJ11 moulded adator with a 4-wire RJ11 phone cable. My pinouts of the back of the DB9-RJ11 adaptor are 2,3 and 5. I am then using a 4-wire RJ11 to RJ11 phone cable to connect from the adaptor to the AUX port. Is this correct?

Anyone help enormously appreciated as I can't seem to get a response from Southern Stars about this.

Tony

AndrewJ
20-01-2014, 11:32 AM
Gday Tony

You MUST NOT plug a serial cable into the Aux port,
on any Meades, as you risk frying things.
The serial comms for an LXD55 is via the 4pin RJ11 cable, but it must only ever be plugged into the base of the 497 type handbox.

Andrew

midnight
20-01-2014, 11:15 PM
Hello Tony,

As Andrew points out correctly, you do not use the Aux port on the LXD55.

Use the RJ11 port on the Autostar handcontroller itself which is normally left not connected.

Also, ensure you have the correct pin assignment so that RX on the third party device connects to TX on the Autostar and TX on the third party device connects to RX on the Autostar and also GND is connected.

Looking at the Autostar RJ11 port :
1 = Autostar RX
2 = Autostar TX
4 = GND

So the final connection is
RJ11 pin 1 (RX) -> DB9 pin 3 (TX)
RJ11 pin 2 (TX) -> DB9 pin 2 (RX)
RJ11 pin 4 (GND) -> DB9 pin 5 (GND)

I have used this connection for a few years on my LXD55 8"SN setup where I used the port for Ascom guiding via a NexImage CCD.

Good luck!
Darrin...

Barrykgerdes
21-01-2014, 05:50 AM
I do not have an LXD55 to test on but I am pretty sure that the mount can be controlled from the auxilliary port. This is not a standard RS232 port but is designed to be used with a special 506 cable kit to connect to a computer. It was designed to use as the computer connection port when the simpler 494 controller was used.

Barry

AndrewJ
21-01-2014, 07:08 AM
Gday Barry

You are correct that there is a special Meade supplied cable that can be used via the Aux port, but as noted, it is not a simple cable, it has active electronics in it. People need to clearly understand that.

The Aux vs Rs232 ports have the following mapping
Pin 1 Gnd vs Rx
Pin 2 Dat vs Tx
Pin 2 Clk vs n/c
Pin 4 12V vs Gnd

so plugging a std wired ( Meade ) serial cable into an Aux port
ties the cables Rx line to the scopes ground
and the cables real Ground gets 12V put back into it. :sadeyes:

( Meade had 4 pins for this function, why they never standardised to prevent this sort of thing is beyond me )



Andrew Johansen Melbourne Australia

acropolite
21-01-2014, 07:11 AM
The cable that you use to control the LXD from your laptop is the correct one. if you have been controlling the mount using that cable, then it would have been via the handbox. Not sure about the Skywire cable but my SkyFi has an additional RJ-Db9 cable which then connects to the Db9-RJ Meade cable. I'd suggest that you get the mount talking via your laptop first to prove it is working then use the connection with the skycable. Also if it's possible to change the baud rate, make sure that your comms speed from the Skycable matches that of the mount.

Barrykgerdes
21-01-2014, 10:09 AM
Hi Tony

You have not mentioned what controller you have with the LXD55. The early type had a 494 controller or a hand controller that just moved the scope and provided simple tracking.

If you have a 497 controller I expect you will have already found that the computer connects via the RS232 socket in the base of the 497 as in the picture. This follows the standard RS232 protocol as all Meade sets can use. This leads me to suspect that you have one of the simple controllers. The LXD manuals are available on the Meade site and If you have not already got one, download it and read it.

If you have a 494 controller or the simple controller there is no RS232 socket on the controller. In this case you need to purchase the accessory cable kit 506. This cable has a 6pin RJ connector from a little box molded into the cable that does the conversion from RS232 to TTL and plugs into the auxiliary socket. There is also an inherent delay caused by the conversion that may prohibit proper control from some computer programs. The Meade Autostar suite works OK and the Software bisque programs work but we had to modify the Stellarium controller to make it compatible.

If you don't have the 497 controller I think the expense is worthwhile considering the use you require of the telescope.

Barry

PS I checked out the Skywire connector and it mentions that it only works with a 497 controller and amongst the list of applicable telescope it mentions the LXD and other series with the 497 controller.

If you do in fact have the 497 controller and can't get a connection it could be due to the allocation of the com port number. The Skywire as far as I can acertain is just an active USB to RS232 connector and we all know how cantankerous these can be at times.

B.G