Jump to content
 

Lenz, LDT and RS bus


alangr

Recommended Posts

I am hoping to use the LDT RS-16-O feedback module with my Lenz system and am now trying to understand how the addressing of the LDT unit works in relation to the Lenz RS feedback bus. As ever, this may be a silly question stemming from a lack of understanding and, if so, I apologise for raising the matter.

 

I think that I understand the way that the RS-16-O unit works having read the leaflet ??™16-fold feedback unit??™ that I downloaded from the LDT website. By setting a suitable starting address it is possible to set 8 feedback flags that go to the LZV100 via the RS bus; the results are then indicated on the LH100 handset in the positions at the bottom of the screen.

 

What I want to do is report back on the status of a number of points which naturally have different addresses. Where I am not clear is with the 8 positions that can be monitored under each (LDT) address. Can these be used for four points (i.e. four different (Lenz) addresses with two positions each), thus allowing both positions of all four points to be reported? Reading the document, it would seem to be possible but I wonder just how the Lenz system picks up the ???8 positions per (LDT) address??™ and deals with them??¦

 

It may well be that the two sets of addresses are simply separate but, if so, then there will need to be some kind of cross-referencing table to allow the Lanz system to know just what the state of the points is...

 

I suspect it is all very easy really but I am in a darkened room at the present and cannot readily see the way out. Can anyone help, please?

 

Cheers

 

Alan

Link to post
Share on other sites

I've programmed and used a RS-16 for detecting track occupancy via a Lenz LB101 but haven't used it for point detection. Hence my understanding may not be complete but I believe the following to be true.

 

You need to understand that each accessory decoder has a decoder address similar to that of a loco decoder. This is NOT the same number as the turnout number used to operate a turnout via the handset! Each address has eight bits, and for a turnout decoder these are normal and reverse for four consecutive turnouts. For my Lenz system, turnout decoder number 1 controls turnouts 1 to 4, number 2 controls 5 to 8 and so on. A further complication is that some DCC systems count from zero rather than one, which changes the above numbering, and I believe the Lenz can be reconfigured to do this. If you have changed this setting then the numbering I suggest here will also change (and I'm not sure how).

 

The RS-16 is given an address on the RS bus by pressing its push switch and throwing the turnout with the number the same as the desired RS bus address. As above, unless the number is 1 it is not the number of any of the turnouts that you wish to feed back through that module! The first eight inputs of the RS16 will then be the eight bits of the address it is given and the rest will be the eight bits of the address one more than the start address.

 

Hence if you hit the RS16 button then F-7-65 on the LH100 you will be setting the RS16 to addresses 65 and 66 and F-6-65 will look at the first eight inputs. You should see a letter "b" on the display - if you just get the number and a dash then the LH100 can't see the device on the RS bus so it is either not connected or hasn't programmed. If this is OK and you pass a current between one of the first eight terminals and the common on the RS-16 then the bit number you just operated should appear on the handset. From your post it sounds as if you have got this far.

 

F-6-66 should then display the other eight bits. 65 and 66 are just examples here, you can use any number up to 127 I think.

 

Lenz reserves module addresses 1 to 63 for turnout feedback and addresses from 65 upwards for general purpose feedback. As I understand it, if a feedback device has the same module address as a turnout decoder, then the system assumes that it is providing feedback for the four turnouts connected to that decoder. Hence if you program your RS16 to address 1 it will provide feedback for the first and second turnout decoders, which should be turnouts 1 to 8. This is the part I haven't tried myself, so I suggest you experiment rather than taking my post as gospel!

 

I think this rather inflexible arrangement is all you are allowed - each RS16 can only detect eight consecutively-numbered turnouts, and if a RS16 is set up in this way then any of these eight that are actually used must be wired back to the same RS16 for feedback.

Link to post
Share on other sites

Thanks, Edwin_m, grist for the mill! I will need to read a few times to get to the bottom of this; I am still exploring - I do not actually have one of the LDT units yet!

 

However, I do not follow your second paragraph. With my LS150 units, I have programmed the individual point addresses, not taken the 'sequential' route. So, for example, I could have points 34, 45, 49, 51, 55 and 58 on the same LS150. What I do not follow is how there are then other decoder addresses.

 

Also, I may not have been clear but I have found that it is not possible to feed the LDT unit straight from the LS150 (I checked with LDT). I will be using the microswitches on the points that I use for the panel LEDs also to trigger the LDT unit. So, as I see it, my problem is how to convert the '8 feeds per LDT address' into the two positions for each of four points each of which has a different address. I could, if necessary, change my point numbers to be aequential but I still do not see how the LDT unit would report different addresses!

 

Thanks for your comments. I am also trying going to LDT to see what they recommend and will let you know if I get a 'solution' to this 'problem'.

Link to post
Share on other sites

I'm not familiar with the LS150 but I'm pretty sure that the RS16 doesn't have similar flexibility in setting its address. To make use of it I think you will need to renumber all the turnouts you want to detect to be in a single block of eight, ending with a multiple of four (eg 1-8 or 25-32), and with no other turnouts numbered within the same block of 8. You then take the address of the fourth turnout in the block, divide it by 4, and this is the address to put into the RS8 (1 or 7 in my examples above).

 

If you use a separate microswitch then you should be fine if you wire up as per the diagrams in the RS16 manual or in the separate circuits leaflet also on the LDT website. I found that using normal 50Hz AC in the detection circuit wouldn't work - I think the detector is picks up each AC cycle as a change of state and therefore clogs up the RS bus with event reports. DCC current is supposed to work but I ended up using smoothed DC. I'm not surprised the RS16 won't work from the LS150 outputs, as I believe the LS150 is powered off AC so probably supplies AC or unsmoothed DC to the point motor. Also if you were to detect the outputs of the LS150 you would only be proving that the decoder has operated - the microswitch also confirms that the point has moved across.

Link to post
Share on other sites

If you must have point position feed-back would it not be more economical to simply use Lenz LS100 point decoders with built in RS feedback? I know they are more expensive than the LS150 and only have four outputs, but you then don't need the LDT units and save all the time and hassle that you are encountering now.

Link to post
Share on other sites

Thanks for your replies. I want point position feedback as I aim to go for RR&Co software in due course. It is (now!) too late to use the LS100 units as I already have most of the LS150s that I need (8 to date). Had I known where I was going before I started. well, yes, I would probably have used the LS100!

 

I still need to figure out just how to do what I want (four points om one LDT address) but I have had a reply from LDT (Peter Littfinski) saying that... 'your model railroad software can fit ... both [pieces of] information (point address and feedbach address) together, to show the right point status on the screen.'

 

So clearly it is possible; maybe I need to play/try!

 

Still, any further comments are welcome!

 

Cheers

Link to post
Share on other sites

If you must have point position feed-back would it not be more economical to simply use Lenz LS100 point decoders with built in RS feedback? I know they are more expensive than the LS150 and only have four outputs, but you then don't need the LDT units and save all the time and hassle that you are encountering now.

 

I have been using Lenz LR101s to provide point feedback for a while - a combination of LS150s and LR101s is half the price of using LS100s.

 

Francis

Link to post
Share on other sites

I use RR&Co without having any point detection, though I haven't run it enough to tell whether it is reliable. You may be able to do something clever with combining detection for a whole route's worth of points into a single RS16 input and then somehow use this in the route proving in RR&Co.

Link to post
Share on other sites

  • RMweb Gold

I use RR&Co (Traincontroller) together with Lenz LS150s and don't use any form of point detection. I rely on TC to show me which way the points are set. This works fine except in a couple of situations:

 

1) The point motor sticks and doesn't throw. But then the LS150 doesn't know that either.

2) You use the Lenz hand-held controller to change points when TC is not running. If it is running, TC updates its display.

 

Apart from these all works fine. I have set up a special "route" which covers one point, and via additional commands added to the route, all other points are reset with a half-second delay between each. This means I can reset all points in the layout (78) with one TC route command, if they're out of sync, but this is a rare occurrence. TC updates its status on disk only when it closes, so if you had a power cut, for example, then TC will have lost all updates from that session as it would not have been closed properly. TC does have its own reset command, but this inserts no delay between each point and causes one or more LS150s to trip.

Link to post
Share on other sites

Hi all,

 

Yes the RS16 is ideal for use in providing feedback info for point position to both the LH100 and RR&CO. For me reading each point on the LH100 is absolutely painful and if it was the only way to display it I think I would not have used it.

 

But RR&CO can make use of the RS16 very easily and is set up as part of setting up each point in the dialogue box for each point. Click on the position control button and just set it up. Its easy when you look at it as it is almost the same as setting up a block occupancy detector. Set the address, 1, 2 3 etc up to 64 and then the input number 1 to 8 for each address. Then set the on state for the sensor and the position of the point it corresponds to and that sit. if you then change the point by hand the point symbol should change as well on the switch board.

 

If you also set up the rest of the position control stuff, it adds further protection for your layout.

 

Alan, I have sent you an e mail answering your questions. Hope it is useful.

Link to post
Share on other sites

Just to add a bit more. RR&CO V7 can monitor routes set for use with schedules. If a point does not set correctly and the train goes off in the wrong direction, RR&Co will know this and stop the train.

 

This function is not enabled by default so you need to do it yourself.

 

Have a look for Watchdog under security settings as part of the schedules properties under the rules tab. Also read the manual for further info about using it as it needs a good understanding of what it does.

Link to post
Share on other sites

Thanks, all. I think that I am now clear with the help that TTG has given me. In summary, as with TTD's post above, once the address of the RS16 is set (say 3 - this is a LDT addrress) there is then implicit addressing and the eight connections cover Lenz addresses 9, 10, 11 and 12 (two connections at a time for points). Why 9-12? It's because each RS16 covers (implicitly) four Lenz addresses so LDT 1 is 1-4, LDT 2 is 5-8, etc. In fact, as the RS16 is a double unit (and so gets two LDT addresses when one is set, 3 and 4 in this case), so an RS16 with address 3 will cover points 9-16.

 

I guess that this was behind what you were all trying to tell me but I was still unclear until I realised about the implicit addressing. Sorry folks.

 

And many thanks TTG; all I need now is time, cash and some patience to completely renumber all of my points...

 

Cheers

Link to post
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...