Heljan End State Feedback

[Dave1964]

I have an issue with trains running off the turntable before it reaches its destination. ITrain suggests an End State Feedback but I don’t know how to set the feedback up. 
Any help appreciated 

 

dave

[jpendle]

Probably a better question for the iTrain forum.

 

Regards,

 

John P

[Dave1964]

I have tried but it’s not an Itrain issue. I have since discovered that Heljan do not provide end-state feedback outputs. 
thankyou

 

[ITG]

I saw your post on the iTrain forum, and being an iTrain learner, I'm in no position to suggest a solution. But I just wondered.... your issue is nothing to do with how iTrain sees (or doesn't) via your sensors, what I assume is a polarity reversal when the table turns through 180 degrees, is it? My own research suggests many current sensors cannot cope with reversed polarity, as I'm considering how best to deal with reversing loop polarity changes/current sensors. This search led me think I may use the new YaMoRC cuurent sensor, which I believe can cope with polarity reversal.

Feel free to ignore if this is a red herring!

Ian

[WIMorrison]

1 hour ago, ITG said:

...My own research suggests many current sensors cannot cope with reversed polarity, as I'm considering how best to deal with reversing loop polarity changes/current sensors. This search led me think I may use the new YaMoRC cuurent sensor, which I believe can cope with polarity reversal.

Feel free to ignore if this is a red herring!

Ian

 

Use one of these AFTER the current sensor.

 

LoDi-KSM Reverse Loop Module for Digital Railways

 

Simples, and means that you only autoreverse the single feedback that you need to, not all 16 😉

[two tone green]

2 hours ago, WIMorrison said:

 

Use one of these AFTER the current sensor.

 

LoDi-KSM Reverse Loop Module for Digital Railways

 

Simples, and means that you only autoreverse the single feedback that you need to, not all 16 😉

Interesting. Like the idea that it does not trip a block occupancy detector due to no power draw. 
 

Have you got one? 

[WIMorrison]

I use the older LS Digital 5410, however I understand that Lodi-KSM are the replacement for them, I am certain James @ DCC Train Automation would confirm that for you.

 

Reverse loop module 5410 and 5420

[two tone green]

9 minutes ago, WIMorrison said:

I use the older LS Digital 5410, however I understand that Lodi-KSM are the replacement for them, I am certain James @ DCC Train Automation would confirm that for you.

 

Reverse loop module 5410 and 5420

I use a frog juicer that feeds a ESU four channel output block occupancy detectors on my turntable. 
 

In effect three outputs are redundant due to the to the frog juicer being on the input side off the detector unit. If it’s afterwards the detector shows occupied all the time as it’s seen as a load. 
 

The Lodi one being not seen as a load would would fit on the output side and free up the other three outputs for other tracks. Nice. 

[Dave1964]

Hi

 

You do not need a reversing module with the Heljan DCC turntable because it has this built in. There is a small zone in the circle where this happens and where no tracks can be laid. 
 

The track bridge supplies can be routed through a feedback detector, I use a Digikeijs one, but that simply tells you if the bridge is occupied. However, there appears to be no way of the turntable reporting back its current position. Itrain will try and guess the position because it knows what commands it has been sent, but this quickly gets out of sync with the actual position as sometimes the bridge moves in a different direction! 
 

in addition iTrain, or any DCC system has no way of knowing when the bridge arrives as the desired location other than an estimated period of time. 
 

Dave

 

 

 

 

17 hours ago, ITG said:

I saw your post on the iTrain forum, and being an iTrain learner, I'm in no position to suggest a solution. But I just wondered.... your issue is nothing to do with how iTrain sees (or doesn't) via your sensors, what I assume is a polarity reversal when the table turns through 180 degrees, is it? My own research suggests many current sensors cannot cope with reversed polarity, as I'm considering how best to deal with reversing loop polarity changes/current sensors. This search led me think I may use the new YaMoRC cuurent sensor, which I believe can cope with polarity reversal.

Feel free to ignore if this is a red herring!

Ian

I have used a DigiReverse module for polarity changes in reversing loops, these are also often used with turntables but not required for the Heljan DCC turntable.   Dave

[WIMorrison]

48 minutes ago, Dave1964 said:

The track bridge supplies can be routed through a feedback detector, I use a Digikeijs one, but that simply tells you if the bridge is occupied. However, there appears to be no way of the turntable reporting back its current position. Itrain will try and guess the position because it knows what commands it has been sent, but this quickly gets out of sync with the actual position as sometimes the bridge moves in a different direction! 
 

in addition iTrain, or any DCC system has no way of knowing when the bridge arrives as the desired location other than an estimated period of time

 

Feedback detection of position involves placing contacts at each stopping position to feedback that the deck has reached the stated position. With some decks this is a simple operation, e.g. Fleischman, don't know about Heljan.

 

Most, but not always all decks work with a pseudo stepper functions (good ones actually use a stepper motor) to place the bridge into an accurate position, often locked in by a detent of some description. The command sent from programs like iTrain are often as accessory commands, specifically a series of turnouts with one end of a position being branch and the other being straight, or hey simply use position 1 as straight and the position 2 as branched, etc.

 

Quote

From the factory there are two preprogrammed positions on the turntable (1 and 2): This means that track 1 will be assigned address 225 Red/curve, track 2 will be assigned address 225 Green/ straight. Track 3 will be assigned address 226 Red/curve, track 4 will be assigned address 226 Green/ straight

 

I also note that the default address for the deck is 57, yet you use 41 - why? 

 

Quote

The control box comes with a default accessory value of 057 (see section 10b for changing the default set digital value) and it occupies the next 25 sub-addresses.

 

Please mind that no other accessory decoder should be located in the range covered by the control box. Please note that the accessory decoder address has no influence on the loco address

.

I suggest that you use the manual to reset the deck to defaults, and set iTrain acco9rdingly.

 

Heljan TT Manual

 

[Dungrange]

4 hours ago, Dave1964 said:

but this quickly gets out of sync with the actual position as sometimes the bridge moves in a different direction! 

 

Is this not an issue with the calibration of the turntable?  That is, section 5d in the manual seems to state when the turntable needs to be recalibrated and section 6b seems to set out how to do this.  To be out of sync, it appears that the turntable motor is either driving the turntable further or not as far as it thinks, which implies it needs to be recalibrated.

 

Sorry, I can't help with the actual question, but hope you find a solution.