What Might RM with LD Know about Positions in the Future

[PJ_model_trains]

@Fishmanoz - @ St1ngr4y

 

I don't think the x,y co-ordinate has anything to do with speed and direction... though I could be wrong.

 

I don't think the x,y co-ordinates has anything to do with layout design dimensions as they are different to the schematic latout sizes. Not to scale. Though I could be wrong.

 

It seems to me the x,y co-ordinate is a simple means of identifying a sensor in the system so that only the tag ID needs to return to RM.

 

But the addition cm (well spotted) adds room for further thoughts???

 

[St1ngr4y]

Hi PJ,

Let us rewind a month or two :-) 

Am I right in saying that we assumed that the sensors would be connected to their own "LD bus" which in turn leads to the LD controlling module? If this is the case, then a packet of information will be sent by a sensor when a train passes over it, and this packet must contain the address of the sensor so that the LD controller knows which sensor was triggered. The only other way is for each sensor to be wired directly to the LD controlling module, which would require the latter to have 48 pairs of terminals, one pair for each port/sensor.

Ray

[hosh]

Is it possible that the x,y cm box is a layout position for simply reminding you of where it is on the layout in the event you wish to locaate it so you could move, replace or remove it altogether?

[hosh]

Clearly any time a sensor is tripped, the sensor ID and train ID is sent to RM. How would it know where the train was if the sensor ID wasn't passed to RM. You would have a bunch of sensors that relay no positional information at all! The sensor ID is a location.

[Fishmanoz]

Just some summary thoughts from the last page or so:

 

I agree if the sensors are on a bus, they will need to send their IDs.  Only if they are wired separately will they not need to.

 

Thanks for posting the setup screen Ray.  I'm going to have to go and check mine as yours is different to my memory (having BOSD troubles with my RM Laptop since a W10 1511 upgrade, a video issue).  I thought mine showed ID, LDM no, and port no, not any linked signal.  I agree the coordinates moved down into the instruction set area, no idea why.

 

Having the coordinates in cm tends to indicate to me they are real distances and not just cell numbers on a schematic.

 

I don't think it is a reminder as hosh just suggested.  You don't need reminding where something is if you can already right click on it in a schematic and relate that schematic position to your layout.

 

I don't see the x,y has anything to do with speed measurement by a sensor.  Speed is distance divided by time so can't be determined by knowing just a single point.

 

I also don't think the x,y has anything to do with ID, that's set by the number you enter in the first line.

 

If you have more than one sensor, you'll know the distance between them, but that doesn't tell you the track length between them, or even the track configuration between them.

 

So I'm still at a loss as to how the info will be used.  That said, it must be useful for something or HRMS wouldn't have put it there.

[Fishmanoz]

And just a terminology thing - sensors aren't "tripped", they make detections consisting of loco tag IDs and very possibly time for the tag to pass the sensor and the direction it is going (whatever direction might mean).

[PJ_model_trains]

Hi PJ,

Let us rewind a month or two :-) 

Am I right in saying that we assumed that the sensors would be connected to their own "LD bus" which in turn leads to the LD controlling module? If this is the case, then a packet of information will be sent by a sensor when a train passes over it, and this packet must contain the address of the sensor so that the LD controller knows which sensor was triggered. The only other way is for each sensor to be wired directly to the LD controlling module, which would require the latter to have 48 pairs of terminals, one pair for each port/sensor.

Ray

 

True Ray

 

Having a LD Bus where lots of sensors will be sending lots of information back, each small in size but considering loco and tender or loco and last carriages from every sensor on every track as triggered there has to be sensor ID.

 

Thanks for bring us back to this  ;o)

 

[PJ_model_trains]

Having the coordinates in cm tends to indicate to me they are real distances and not just cell numbers on a schematic.

 

All Hornby locos are calibrated and speed tested, could the cm relate to a calculation from knowing the loco scale speed. If so how. (Just floating thoughts)

 

I also don't think the x,y has anything to do with ID, that's set by the number you enter in the first line.

 

Good point.

 

If you have more than one sensor, you'll know the distance between them, but that doesn't tell you the track length between them, or even the track configuration between them.

 

This falls short on all views I think as the layout dimensions on the layout are not proportional to the schematic layout.

 

So I'm still at a loss as to how the info will be used.  That said, it must be useful for something or HRMS wouldn't have put it there.

 

Best answer all day... don't give up  ;o)

 

[PJ_model_trains]

And just a terminology thing - sensors aren't "tripped", they make detections consisting of loco tag IDs and very possibly time for the tag to pass the sensor and the direction it is going (whatever direction might mean).

 

This has been mentioned a few times, hosh keeps using the term 'tripped' I wonder if this is a term used with BD?

 

All sensors are sleeping, until a tag 'activates' the sensor, it reads the tag and sends the appropriate data to RM for processing and goes back to sleep.

 

[hosh]

And just a terminology thing - sensors aren't "tripped", they make detections consisting of loco tag IDs and very possibly time for the tag to pass the sensor and the direction it is going (whatever direction might mean).

 

http://www.safewise.com/resources/motion-sensor-guide

[hosh]

And just a terminology thing - sensors aren't "tripped", they make detections consisting of loco tag IDs and very possibly time for the tag to pass the sensor and the direction it is going (whatever direction might mean).

 

This has been mentioned a few times, hosh keeps using the term 'tripped' I wonder if this is a term used with BD?

 

All sensors are sleeping, until a tag 'activates' the sensor, it reads the tag and sends the appropriate data to RM for processing and goes back to sleep.

 

 

http://docs5.mios.com/doc.php?language=1&manual=1&platform=2&page=sensor_scene

[PJ_model_trains]

PJ, on direction:

 

On direction, clearly there is a forward or reverse set in the throttle.  But we already know if there is a reversing loop, a loco can pass a sensor just outside the loop, then proceed around the loop without changing its throttle direction, and arrive back at that same sensor heading the other way.  So I think direction of passing over a sensor provides information not necessarily available  from the throttle.

 

Surely that depends how you view this...

 

If a loco is going forward into a reverse loop section when it comes out it is still going forward although to the eye it is going in the opposite direction. What has changed is how it receives its power not what direction is appears to be moving.

 

Forward is forward from the loco prospective it cannot be reverse. 

 

If RM says loco003 forward 30mph it goes forward. RM told the loco decoder this, the loco carries out the command it was given, irrespective of whether it is entering or leaving a loop of track.

 

Regarding movement of a loco, other than speed and stop, the loco only knows forwards or reverse.

 

[Howbi]

PJ said..."Having a LD Bus where lots of sensors will be sending lots of information back, each small in size but considering loco and tender or loco and last carriages from every sensor on every track as triggered there has to be sensor ID"............There is NO LD bus, we are already told that 48 sensors can connect to each LD Module........In the Loco Detection Settings box there is a choice of LDM1 and LDM2 each with a selector of 1 - 48 port ID's, total 96 sensors......so the Sensor ID's will be addressed as M1/1-48 & M2/1-48 I guess.............It is interesting to note that the Signal Settings box does not require X.Y co-ords when the LD box does?  HB

[westernwill]

I disagree with you here PJ.

Surely the important thing from the sensor point of view is which direction the train is moving irrespective of which direction the loco motor is running.

i.e a track running east to west with a sensor in it. A loco can move over this sensor eastwards irrespective of whether the loco is running forwards or backwards.

Surely that is the information to be sent back to be acted upon.

 

 

[PJ_model_trains]

PJ said..."Having a LD Bus where lots of sensors will be sending lots of information back, each small in size but considering loco and tender or loco and last carriages from every sensor on every track as triggered there has to be sensor ID"............There is NO LD bus, we are already told that 48 sensors can connect to each LD Module........In the Loco Detection Settings box there is a choice of LDM1 and LDM2 each with a selector of 1 - 48 port ID's, total 96 sensors......so the Sensor ID's will be addressed as M1/1-48 & M2/1-48 I guess.............It is interesting to note that the Signal Settings box does not require X.Y co-ords when the LD box does?  HB

 

Hi HB

 

The LD sensors will be able to connect to a LD Bus. The LD Bus will then connect to the LD Controller Unit (Similar to an eLink one).

 

You can have as you say, two modules, but each will be able of coping with up to 48 sensors. (2x LD Bus')

 

Now that is as I understand it based on discussions to date.  But if each sensor is wired back separately to each port 1-48 that is a lot of wiring. But if this is what is required it would explain how a sensor is already known and only the Loco tag ID would need to be sent back.

 

Having said that there may be a learn mode where a LD Bus is used but each sensor is programmed one by one and the LD controller stores those port connections in memory in the module.

 

I am aware a few of us are thinking as I have stated at the top of the post but think it is worth listening to what others have to say also.  ;o)

[PJ_model_trains]

I disagree with you here PJ.

Surely the important thing from the sensor point of view is which direction the train is moving irrespective of which direction the loco motor is running.

i.e a track running east to west with a sensor in it. A loco can move over this sensor eastwards irrespective of whether the loco is running forwards or backwards.

Surely that is the information to be sent back to be acted upon.

 

Hi westernwill

 

I understand where you are coming from but,

 

- how does the loco driver view things - the front of a train is the front of the train (keeping to steam locos for this discussion)

- how does RM consider movement of the loco - forwards is forwards

- train enters loop going forward - it leaves the loop going forwards

 

I remain open minded and welcome debate but at present this is how I see it.

 

[St1ngr4y]

Has anyone noticed this statement on page 96 of the latest RM guide, under the heading of "Direction Indicators" ...

 

"You will need to place arrows on stretches of track when using the optional Loco Detection system. "

 

This suggests to me that, if the tag is a bar code, for example, the sensor may be able to tell which way the tag has swiped across it, thereby being able to work out which direction the tag is moving, ....... maybe ??? Would this mean that it would be necessary to orient the sensor in a particular direction when installing it ??? 

Aaagh! my brain hurts - I'm going to give it a rest for a week or two.

Ray

[Howbi]

@PJ............Hornby have already specified an LD Module having 48 ports to enable the connection of 48 sensors..............not for connecting an LD Bus, simply can't work connected together.........the sensors are not intelligent nodes so cannot be bussed.   HB.

[PJ_model_trains]

Has anyone noticed this statement on page 96 of the latest RM guide, under the heading of "Direction Indicators" ...

 

"You will need to place arrows on stretches of track when using the optional Loco Detection system. "

 

This suggests to me that, if the tag is a bar code, for example, the sensor may be able to tell which way the tag has swiped across it, thereby being able to work out which direction the tag is moving, ....... maybe ??? Would this mean that it would be necessary to orient the sensor in a particular direction when installing it ??? 

Aaagh! my brain hurts - I'm going to give it a rest for a week or two.

Ray

 

Hi Ray

 

This was raised a few weeks back but, the directional arrows have been available to add on track for some time.

 

If I remember correctly it had also been discussed prior to that and the arrows were considered to be directional indicators for say loops, especially when we have two, three of more loops nested some clockwise, some anti clockwise.

 

But if they are for use with LD then this would raise a big question... what happens when we run trains bi-directionally? Would it distinguish the arrows only for the direction they are intended and ignore the others facing the opposite way?

 

It is therefore a good question Ray as it states...

"You will NEED to place arrows on stretches of track when using the optional Loco Detection system. "

Not that we may want to or could but we will NEED TO!

 

Hornby have certainly kept us waiting and had us guessing.

 

Do you think they are laughing to each other saying...

'At last we have found a way to get them to read the manual'

 

Probably followed by Cheers, Happy New Year  LOL

 

[hosh]

Has anyone noticed this statement on page 96 of the latest RM guide, under the heading of "Direction Indicators" ...

 

"You will need to place arrows on stretches of track when using the optional Loco Detection system. "

 

This suggests to me that, if the tag is a bar code, for example, the sensor may be able to tell which way the tag has swiped across it, thereby being able to work out which direction the tag is moving, ....... maybe ??? Would this mean that it would be necessary to orient the sensor in a particular direction when installing it ??? 

Aaagh! my brain hurts - I'm going to give it a rest for a week or two.

Ray

 

Yes, I noticed and posted about it a few weeks back.

 

There is no way that a sensor can know which direction it's reading a barcode in. It could tell forward from reverse perhaps, but that'd already be known anyway.

 

If you wanted direction fed back to a system then you'd need 2 sensors and then know the order of tripping.

 

Better yet, have a system that tracks all trains through time and thus knows where every train is, what it's doing and what direction it's headed in. :)

[PJ_model_trains]

@PJ............Hornby have already specified an LD Module having 48 ports to enable the connection of 48 sensors..............not for connecting an LD Bus, simply can't work connected together.........the sensors are not intelligent nodes so cannot be bussed.   HB.

 

Hi HB

 

Interesting point and it does appear to point in the direction you are stating.

 

Taking your last statement though, I think it could work with a LD Bus if the Module had memory to save the data for each port and could be done in a learn mode, one by one. But it would need learn mode and would need to set each one up individually, it would also need the ability to save the data to inside the modules. With todays technology I do not see it as impossible.

 

That aside, 48 individually wired port sensors per module is probably the cheapest for them and probably the easiest for them to do. They are also sure of a direct port connection for each sensor. I do wonder however, if this is the route they have taken, why they have done so, as a series of decoders linked back to the main module could have worked and probably given them more profit from the additional items sold. Maybe by keeping it in the main module they are keeping everything in house, saving the risk of going down the decoder route and us buying other manufacturers decoders and not their own.

 

[westernwill]

Hi again PJ

Consider this scenario.

There is a branchline terminus and we want trains to stop at the station platform at the same point every time.

Now we can write a program in RM to simulate that but we know that it won't necessarily stop in the correct place.

As I understand it, and I admit my knowledge of LD is pretty thin, we can place a sensor just before the station and when a train passes over it information is sent to RM which then issues our command to that train to decelerate to 0.

Now if the sensor will only send that information when the loco is in forward gear, then when say a tank loco with the carriages attached to the front is approaching in reverse gear the train will carry on and crash into the buffers. This is not what we want to happen.

So i still maintain that the fact that the train is moving towards the station must be the direction that is sent back irrespective of the gear that the loco is in.

I am probably wrong but I cannot see how it will work otherwise.

Westerwill

[Howbi]

Hi PJ............Further to my last post, consider the purpose of the R8247 Accessory decoder which can manage 4 points..............you can't connect those points to a bus and send a data instruction along the bus and expect one to work on it's own without a decoder to ID it...............The sensors do not have IC's built in, they would physically be too big to fit in the sleepers as per Hornby's illustration so all the ID data is handled in the LDM  before relaying to RM.  As you suggest, Hornby have to work to a budget to make this system marketable at reasonable cost. HB.

[RDS]

... my knowledge of LD is pretty thin ...

 

Don't worry about that - everyone's knowledge of LD is pretty thin.

[Fishmanoz]

Following on from HB on sensors and the possibility of bussing them.  If they were bussed, then there are two choices: either they come pre-coded in sets of 48; or they have to be programmed to an ID code.

 

There's been no indication to date of having to buy them in sets of any size (it would be possible for instance to buy 8 different sets of 6, rather than one of 48), so I'm going to discount that for now.

 

If you have to program them, then either they would have to go on a programming track or they would have to have a learn mode.  I'd suggest on a programming track is highly impractical.  That leaves learn mode.  Due to size, unlikely that learn mode is entered by throwing a switch, like an accessory decoder, but a specific coded signal could do it.

 

As for room for the electronics to do the modulation onto and off the bus, in terms of today's component density, there's acres of room between sleepers.

 

So don't completely write off the idea of a sensor bus, maybe even one using the new NMRA LCC standard.  But st this stage, I think it more likely they are wired individually.  Fence-sitting I know, but that's the balance of probabilities in my speculation.