Train Detection for a Grade/Level Crossing system

[supagav]

Hi,

I just wondered if anyone had any ideas or suggestions concerning the Massoth Train Detection module?

We recently installed a US style grade crossing (level crossing) flasher unit and sound module from Shiloh Signals on our line. The system runs off small push-to-make sensors which are triggered by the flanges of a passing wheel. It works well at the moment but it does have some big drawbacks. Here are a couple of photos showing it installed:

One of the biggest problems is that the unit is switched on by one sensor as it enters the town, and then switched off by a sensor on the other side of the town as it exits. A train therefore must pass through the town if it is to successfully switch the system on and off. This would be fine under normal circumstances but as it is a destination point for switching and shunting, trains often enter and leave in the same direction and thus cannot trigger the unit to switch off after they pass.

I would like to instead trigger it via DCC using a detection module so that as long as anything is in the town area then the flasher system will be on. I thought to hopefully dispense with the sensors and control the flasher system with a small decoder (function only or maybe a single channel accessory decoder?) and with my Massoth system this could in turn be triggered by the presence of a train? My question is this, would this potentially work as I already have a feedback module in a drawer collecting dust, it just needs the RC upgrade? Is it easy to do with the 1200Z?

Secondly, how sensitive is the Massoth detection unit? I know a loco would trigger it off but would the lights in say a caboose? The reason I ask is that I don't want it to stop until everything has cleared the crossing. The third problem is that there is a 4 channel point decoder fed from the in the area controlling the two points (underneath the petrol station in the photo!), would that also cause false triggerings of the module?

Many thanks in advance for your thoughts and ideas!

 

[supagav]

Hi folks,

I'm sorry to bump this thread again but I also have another question if anyone can help?

I understand that under "Switch Drive" in the Massoth Navigator menu, outputs from a feedback module can be used to trigger EPL drives (point motors and LGB signals.) I was just wondering if these outputs can also be used to control a decoder, for example a function only decoder? Or maybe a Massoth switch decoder which was used to drive a lighting circuit for example? Is this kind of thing possible?

Many thanks in advance,
Gavin

 

[don9GLC]

Hi Gavin,

I would suggest that you should first investigate what is possible with your Shiloh Signals Xing unit and what connections / contacts are required. Even if you do get the track occupancy information back to the DCC system central station you need to know what contacts and connections are required between a function decoder and the Xing unit.

From the Shiloh website it seems they have a relationship with CIRCUITRON and in turn they offer a number of Xing and detection units. Some are single direction only and others appear to be bidirectional but I don't think as standard they offer anything that exactly suits your needs.


A while back I was considering using Massoth Train Detection Modules but at that time they were not available. So I don't have any practical experience with them.

However I studied the operating instructions to establish if they were what I needed to interface with a central computer control system. As with connecting several different 'off the shelf' electronic solutions, it all depends on what you want each system to do. The Massoth system did not suit my requirements.

I'm not sure what Massoth module you have.

The Massoth Train Detection Module, Dimax 320R (item #8170501) can be connected to the Massoth Feedback Module, Dimax 280R (item # 8170001) which is then connected to the Central Station with this final connection by either bus wiring or the optional radio link, all as described in the Massoth operating instructions. If you have trouble downloading them, please PM me and I can give you a link to my own copies.

The Feedback Module can be used with reed switches or other contact arrangements to operate in a form of track detection mode without the Train Detection Module, but with bidirectional operation and even more switching within the Town Area you may have problems getting the logic to operate as you might want.

This post is probably too long already so I will separately post some technical details of the Massoth modules.

Don

 

[don9GLC]

Massoth modules

The Massoth Train Detection Module has two user selected (by jumper connection) minimum sensitivities, 5mA and 25mA. These values were chosen to allow detection of most decoders and illuminated stock but if you have only a single car in the town area with a single led it will probably not trigger. You can get round this by adding a parallel resistor if its a problem in practice. So the Massoth Train Detection Module is probably sensitive enough for your purposes.

The Massoth Feedback Module effectively takes a switched input and converts it into a form that can be sent back to a Central Station. That might be useful for simple automatic operations for example shuttle where the Central Station can be configured to respond. The examples given (in the Navigator operating instructions) are shuttle, station stopping and and route setting. You might be able to drive a function decoder to interface with the Xing unit but as mentioned in my previous post you will need to know what contacts / connections the Xing unit requires.

The Train Detection Module is activated by the current used in the section of track it supplies, 5A maximum. If you connect the switch drives to the Town Area track they may spuriously cause the Detection Module to trigger and cause intermittent random operation of the Xing unit. If you decide to use the Train Detection Module, the switch decoders (and switch drives) should be connected to the main line. It 'might' work connected to the Town Area tracks but its not necessary and could cause difficult /intermittent problems.

The CIRCUITRON website has a useful comment when discussing bidirectional units. In real life the dispatcher has to manually assign a direction of travel by operating a switch. This could be a good idea in model form as well!!!

Don

 

[CoggesRailway]

I'd love to help, but I would have as much advice on how to establish you railway in a geo-stationary orbit!

I know it is off topic, but these are stunning photos and more in a pics thread would be enjoyed!

Ian

 

[supagav]

Don, many thanks for the reply! I really appreciate your thoughts.

Firstly the easy things! If I went down this route I think the first thing would be as you say to relocate the feed for the switch decoder back out onto the mainline so the points are not connected to the detection circuit, but instead are feed by normal DCC track input. This would also be the same for the crossing unit power input as it taps in on separate track feed too. Both of these could easily be remedied to avoid any potential triggering problems.

We currently use quite a few of the LGB american style semaphore signals as whilst they only fairly close to the prototype, they are very durable and work well outdoors. We've just got hold of a Massoth Train Detection module as well as the radio upgrade board for our existing Feedback Module, so I think we may try some simple automation using these signals as they are effectively just big EPL drives! I think I'll play around with the Massoth system and try automating our signals, then leave the Shiloh Xing until we become more familiar with it all. I plan to contact shiloh and see if they have any ideas about how to drive the unit using DCC.

As for the crossing at the moment, I think I may just mount a temporary manual push-to-make switch near the crossing location, outside of the railway, so that the operator can close the Xing circuit if the train doesn't and just manaully switch off the unit after the train leaves town in the same way. Its not elegant but it will work for our operations at the moment.

 

[supagav]

In regards to the CIRCUITRON comment, with the bidirectional thing could a switch be the answer??? Hmmm... Flip a small switch so that the direction of travel is reversed when the train is in town, thus the opposing contact now becomes the correct one...hmmm...again I'll contact shiloh I think and ask!

Many thanks again for the ideas!

PS: Ian, thanks for the kind words! Any compliment, off topic or otherwise, is always gratefuly received! I'll try and get some pics up when I can