Select / Xpressnet cabling

12203 Views 19 Replies 8 Participants Last post by Doug, Apr 29, 2007

dualfuel

Discussion Starter · Dec 30, 2006 (Edited by Moderator)

I am sure this question will be raised by many in the future....

I have 2 Select units, and want to connect them up so I have two 'cabs'.

I understand that the so called 'buddy cable' that hornby briefly mention is a RJ12 cable - basically the same kind of cable a computer modem uses but using 6 wires instead of 2 or 4, which is RJ11 instead.

I don't particularly want to have to make my own, but I am struggling to find anyone in the UK that can supply a 6-way RG12 patch cable to do the job. All I seem to get offered is a 'kit' which consists of the RJ12 connectors and a crimping tool !

Also, is this cable supposed to be a straight through (pin 1 to 1, pin 2 to 2 etc) cable or does it have cross wires (Tx, Rx, Power or what ever the 6 wires are used for)? I can find no info specifically telling me this, and hornby do not yet sell this 'buddy cable', which is a bit poor really.

Can anyone help confirm the cable 'pin-outs' and wire function allocations, or suggest a decent RG12 cable supplier?

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darobi

· #2 · Dec 30, 2006

Hattons have them listed for next year release.

R8235 Select Walkabout £55.00
NEW 2007
R8236 RJ12 leads £5.00
NEW 2007
R8237 RJ12 Connection Socket £2.00
NEW 2007

When they are out in the year it doesn't say.

Darren

dualfuel

Discussion Starter · #3 · Jan 1, 2007 (Edited by Moderator)

I have made a bit of progress on this - the RJ12 cable is a cross-over cable not a straight through cable according to Hornby. Is this the standard for a Xpressnet link cable? I assume it will be pin 1 to 6, 2 to 5, 3 to 4 etc as a full Xover cable.

I have looked at a Lenz LA152 Xpressnet port adapter, and this comes with an RJ12 cable, but I could not tell if it was a Xover cable. Can anyone confirm for me?

The hornby official release items for linking Selects and Elites do not look like appearing for a while - I would guess and say they will appear the same time as the Elite, but maybe that is optimistic!

Anyway, I have an RJ12 cable en-route to me, which I shall no doubt get working somehow!

Doug

· #4 · Jan 1, 2007

I saw that a Hornby representative mentioned 'Crossover' on the Hornby site.

This does throw a bit of confusion into the party.

Traditionally, XpressNet is not crossover - at least not with the cabling. There are 4 terminals L, M, A & B. The connectors are marked LMAB on the devices and L connects to L, M to M, A to A and B to B. Perhapos there is some sort of crossover inside the units. Not sure. I think Hornby are mixing up XpressNet and Ethernet protocols. With Ethernet, You use straight wires if you connect to a hub or router (which manages the cross-links) and you use a crossover cable if you connect two devices directly. Basically because one wire is out put and one is input and for two devices the output has to talk to the input of the other.

The 2 extra wires on the outside of the RJ12 connector on the Select are used for boosters.

dualfuel

Discussion Starter · #5 · Jan 7, 2007

So far I have had no success with connecting the two selects together. I have made a break-out patch cable to allow swapping over of pairs to see what happens.

Basically, apart from pins 2 and 5 which have the supply voltage on which must be straight through wired 2-2 and 5-5, the other pair configurations do not change the outcome of trying to set up a master / slave in any way.

According to the manual this is what should happen:-

Master - connect RJ12 cable to Xpressnet port, LCD should remain with '03' on screen
Slave - connect RJ12 to Xpressnet port of slave, Slave should display 'HC'

Pointless going on to the next step, because at this point it all goes wrong - both units display 'HC' (for Hand Controller or Slave / walkabout) and neither will take control as a Master ('CS').

Maybe a faulty controller (or two), but I have tried all combinations of pin to pin arrangement and using each Select for both Slave and Master configuration. I have given up for now until I get some more info from Hornby.

Hornby have announced the 'Select Walkabout' unit is coming out almost as if it is a modified Select specifically for being used as a Slave. Maybe two standard Selects are not supposed to work together? Another reason in my view to why Hornby should have delayed the launch of this product until they had a clear suite of products to pick off the shelf.

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Doug

· #6 · Jan 7, 2007

I'd like to speak to someone who tested this product prior to it's launch.

If anyone reading is that guy or was part of the team, please email or PM me.

Gary

· #7 · Jan 7, 2007 (Edited by Moderator)

Have Hornby ever claimed that 2 Selects can be connected together?

The answer to the question if anybody asks is that 2 Select units cannot be connected together.

Hornby have said the Select can be connected to an Elite and used as a walkabout unit. Surely the Select will not have the communications hardware on board to support a connection with another Select on its own and the price reflects this.

I am taking the newly announced Walkabout unit as being a standard Select for connection to an Elite and not able to act as a stand alone console. It has a lower price and the only difference probably is the lack of a 1 amp power plug. That seems a logical move and a sensible move on the part of Hornby.

If anybody wants to use two Selects as seperate cabs this can be done by connecting through the Elite console.

Surely it would have been sensible to be patient and wait for the Elite console to be available before purchasing a second Select for use as a walkabout. And this surely has to be the recommendation to anybody considering this.

Happy modelling
Gary

PS Whilst the efforts of those who are experimenting with a Select console to try and get more out of it is to be commended it should not be seen as a failure of the product if you cannot actually get more out of it than Hornby claim it is capable of.

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dualfuel

Discussion Starter · #8 · Jan 7, 2007

Gary - page 20 of the select manual - it quite clearly states you can connect up to 7 select walkabout units so yes the select can be configured as a master and 7 slaves - you do not need an Elite to do so.

The reading of the manual indicates the term 'walkabout' purely to mean 'slave', but this is a bit open to interpretation.

There is also a reply on the hornby site to a message on this subject suggesting the use of a crossover RG12 cable to connect two selects together.

Why do you say Hornby have never stated this - its in the manual, have you ever seen a Select or used one?

Gary

· #9 · Jan 7, 2007 (Edited by Moderator)

3

Quite right.

I didn't realise this so my earlier thoughts are now different!

The manual refers to "Select Walkabout" unit.

I do now agree that Hornby do not make it clear that there is a difference between a Select Console and a Select Walkabout unit.

What I am worried about now is that I will not be able to connect my Select Console to an Elite Console which I did have in mind.

Hornby say in the 2006 catalogue that the Select can be used as a Walkabout companion to the Elite. They make no mention of the Select being able to be used as a Walkabout companion to another Select. This is a very recent change on the part of Hornby!

Happy modelling
Gary

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dualfuel

Discussion Starter · #10 · Jan 7, 2007

Going on the fact there are built in facilities to set-up each standard 'Select' as a command station (C5) or a walkabout (HC), I think it is likely the only difference between a 'Select' and a 'Select Walkabout' is likely to be the packaging - i.e. the walkabout will come with a cable and / or hub ?

I can configure my two units individually, one as a Master, one as a Slave, but they still won't talk. The way you are supposed to do it (as on P20 in the manual) results in both units going into 'Slave' mode 'HC' and the only way to one back into C5 command station mode is to disconnect them and reset!

It could still be a simple cabling issue, but not sure how it can be different to what I have tried - there are only so many combinations with a 6 pin cable. Could be I have a fault on one unit also, but not sure yet.

Dennis David

· #11 · Jan 7, 2007

... or maybe it's a software fault. Is it possible to update the software in a Select should Hornby come out with a patch?

Nick B

· #12 · Jan 9, 2007

Hornby have announced the 'Select Walkabout' unit is coming out almost as if it is a modified Select specifically for being used as a Slave. Maybe two standard Selects are not supposed to work together? Another reason in my view to why Hornby should have delayed the launch of this product until they had a clear suite of products to pick off the shelf.
[/quote]

I would suggest the walkabout unit dispenses with the transformer which is not required, thereby offering the right priced pacakage for the customer! In relation to the cables, they are available from shops in the US for very reasonable prices. (I cannot locate the shops name I identifid; when I do, I will post it.)

Doug

· #13 · Jan 10, 2007 (Edited by Moderator)

I have had an email from Hornby confirming that the leads should not cross-over.

Use straight leads and if you would like to connect more than two units together, use the Lenz LA152 panel adaptor until Hornby release their sockets.

The LA152 (above) connects to the LMAB output of my Lenz LZV100 and then I can add XpressNet devices using the RJ12 sockets or DIN plugs.

The black lead is a 6-wire RJ12 lead fitted with a RJ12 plug.

Remember that only one Select unit should be connected to a transformer - this is the 'master' controller. The other 'slave' controllers take power from the 'master' controller.

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mthornton

· #14 · Jan 10, 2007

QUOTE (Gary @ 7 Jan 2007, 21:00) <{POST_SNAPBACK}>Surely the Select will not have the communications hardware on board to support a connection with another Select on its own and the price reflects this.
The hardware for any connection to XPressNet is the same. The 4 lines consist of two for power and the other two for data. Reading and writing both use both data lines (unlike RS232 which has a seperate input and output lines). As noted elsewhere there is no such thing as a crossover cable for this type of communication.

Perhaps the master 'select' is identified as the one which has a transformer attached --- the slave gets its power over the XPressnet connection. If you attach a transformer to both they may get confused.

Doug

· #15 · Mar 12, 2007 (Edited by Moderator)

3

There has been a development on the Hornby site where someone has finally got two Hornby Select DCC units to work together. It has taken nearly 4 months to figure this out, but anyway...

It seems that twisted cabling is the solution.

Using RJ12 connectors, you should use Cat 5 Ethernet cable with 6 twisted pairs.

The outer two pins of the RJ12 shouldn't have any affect on the XpressNet as the spec only uses the pins 2 to 5.

RJ12 and cable

Pin assignments

What has been the problem: Standard RJ12 to RJ12 is straight cable. Quite often telephone cable is straight and not twisted. On my old Arnold DCC system, they do suggest to twist the A and B wires of the LMAB XpressNet BUS, with 20 twists per meter. The A and B wires are the two middle signal wires.

In the image below, the A and B wires are twisted and the L and M wires are twisted.

Arnold LMAB XBUS

Conclusion: XpressNet doesn't really call for twisted pairs when connecting devices together as far as I know (my Lenz unit uses straight cabling). the older XBUS did though, so it seems that the Hornby DCC engineers have perhaps borrowed some older technologies. XBUS perhaps?

If Hornby is using an XBUS between Select units, they should have know about this from the start as they acquired Arnold as part of the Lima group in 2004... ;-)

If Hornby can please clarify on what exactly is going on here, I'll gladly put the info up.

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Gordon H

· #16 · Mar 12, 2007

QUOTE (Doug @ 12 Mar 2007, 10:09) <{POST_SNAPBACK}>Using RJ12 connectors, you should use Cat 5 Ethernet cable with 6 twisted pairs.
That looks like two daisy-chained twisted pairs to me, same as XBus ever was.

QUOTE XpressNet doesn't really call for twisted pairs when connecting devices together as far as I know (my Lenz unit uses straight cabling). the older XBUS did though, so it seems that the Hornby DCC engineers have perhaps borrowed some older technologies. XBUS perhaps?
The need for twisted pair connection is automatically implied by the use of RS485, which is a differential standard. The fact that the power pins are also twisted is merely a consequence of the convenience of using a two pair cable. There is no hardware difference between the XBus and XpressNet standards as such, it's all in the protocol.

Nick B

· #17 · Apr 27, 2007 (Edited by Moderator)

Some time ago, I promised to provide the details of a shop in the US which sells RJ12 cabling incredibly cheaply. I imported enough cables to set up my Select units remotely around the layout and be hooked back to my Elite which arrived last week.

The web address of the shop is www.litchfieldstation.com. Their service was excellent.

I am experiencing the same connectivity issues as outlined in the other postings here. Has anyone successfully got either two Selects to talk, or a Select to talk to an Elite? Gary, you seem to be a real resource for testing/understanding the Hornby stuff - any ideas?
I have sent a note to the Hornby DCC help centre and await a reply.

Doug

· #18 · Apr 28, 2007 (Edited by Moderator)

2

Looking at this cable supplied from www.litchfieldstation.com (left),
it seems that the cabeling is flat telephone-like cable. This should
work fine on must XpressNet or Loconet DCC systems, but
unfortunatly as we have determined, the Hornby uses a type of
RS485 network (XBus) that requires the to middle (signal) wires
has 20 twists per meter in the cable. Ethernet cable should work.

To try it out (as suggested here or elsewhere) cut your flat cable
about 2 to 3 inches from the plug, bear the wires. Connect these
wires to a section of Cat-5 Ethernet cable. Do the same on the
other end.

With XpressNet, you have 4 important wires LMAB. If there are 6 wires, the two outer wires do nothing. See this diagram:

The A and B wires of the LMAB XBUS need 20 twists per meter.

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Nick B

· #19 · Apr 28, 2007

Thanks Doug. looks like my £12 worth of cables and postage were not so cheap after all! I think I will bin it and buy the ethernet cables you talk about.

I would still welcome a member to state they have successfully connected two Selects or a Select to an Elite!

Do we know what the real release date is for the Hornby factory connection gear is, and how long they intend to make the cables?

Doug

· #20 · Apr 29, 2007 (Edited by Moderator)

Don't bin the cables as you need the RJ12 connectors. Ethernet comes with RJ45 connectors that won't fit the XpressNet ports of the Select and Elite.

There have been a few people connecting Selects together and Selects to Elites.

On the Hornby Forum, look here and here.

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