Control Bus and Throttles

ZTC Control Bus in the Garden - updated 22 May 2007

I have started to install the DCC control bus in the garden. The photographs show twin sockets for the controllers in the lower box. The upper box houses a 25 pin D connector for remote control of points and signals (more on that some other time). The right hand photograph shows the covers on to protect from the weather.

I bought a 500ft reel of cable from Rapid Electronics reference:

02-0544 Twisted 2 pair data cable with overall screen - Type 1

This may be over specified but it seems to work, the reel should last out my lifetime and it is not much more expensive than buying shorter lengths by the metre. The cable runs in heavy duty hose pipe from Wickes which is bright yellow, hence easy to see. It runs on the ground under the baseboards and won't be visible once the plants have grown up to baseboard height.

After some discussion on the DCCUK mailing list I opted for 8 way mini DIN chassis sockets from Maplin (part no.JX12N). It remains to be seen how well they will weather but at least my ZTC controllers will plug directly into the sockets. The sockets are mounted in cast aluminium boxes from Maplin. So far I have only used the 50mm square boxes. Two sockets will fit in one of these with a piece of Veroboard to solder all the connections together. The most difficult part is soldering wires to the sockets but only four connections are required. I find it helpful to feed a short piece of brass tube over the pins to hold the wires in place before soldering. I used heat shrink tubing to keep the wires apart. A brass screw holds the metal box to the woodwork and I used a solder tag to connect the screw to the drain wire in the cable.

I used an external junction box from Wickes to protect the sockets from the weather. I cut the back to fit over the aluminium box and drilled holes in the corners to screw it to the woodwork. The boxes are quite robust once they have been screwed to the woodwork.

Lenz web site includes a description of XBUS. ZTCs web site includes pages on Adaptor Lead for Connecting Lenz LH100 Hand Controller to ZTC-511 and Adapter Lead for Connecting ZTC-550 to Lenz LZ100. These pages include pin outs for the X-Bus and booster cable. From this information and a study of the ZTC Adaptor (part ZTC308) I guessed the ZTC pin outs to be:

M Ground
B - RS-485
A + RS-485
NOT USED but connected through ZTC-308
C Control Bus - not needed for slave controllers
D Control Bus - not needed for slave controllers
NOT USED but connected through ZTC-308
L +12 volts according to Lenz but note on ZTC-550 page suggests +18v

I used one twisted pair for A and B and another for M and L. The cables are connected 1-1, 2-2, 3-3 and 8-8 with no crossed wires.

The control bus was installed in August 2004 and is still working in May 2007. There is no sign of corrosion in the socket boxes, so far!

25 August 2010

The 6 Fulgurex point motors (in the garage) are controlled by DCC from a Lenz LS150 Accessory Decoder. Originally I connected this into the ZTC system used for controlling locos but at the moment I am using my NCE PowerCab for this independently from the rest of the DCC system. The points for a particular siding can be changed using a PowerCab macro.

I have installed two home signals inherited from my father as shown below. The patio bridge and entry through the wall to the back room can also be seen as well as the CCTV camera on the wall.

The left hand signal controls entry to the back room from the junction and the right hand (cleared) signal controls entry from the loops to the back room. They are controlled by servos which are installed in the black ABS boxes below each signal.

Eventually they will be replaced by proper SR signals. The left hand one also requires a Shunt Ahead arm so that the triangle can be used to turn a loco while a train is standing on the section indoors. This is likely to be the first operation requiring an extension to the block instruments. One possibility is to double up on the Is line clear? switch and LED to include Is line clear for shunt ahead?

I am also considering using CTI to substitute for the back room signalman when the panel (box) is switched out. The junction and loops instruments would then interface to CTI instead of the back room block instruments Only a simplified functionality would be provided such that a pushpull train could be accepted and released from the indoor section and an engine could be turned used the shunt ahead.

23 November 2010

I have finally got all the pieces in place for wireless throttles around the garden. The signal from my Netgear router would not cover the whole garden but I have just bought a TP Link outdoor wireless access point (TL-WA5210G) and first tests suggest it will be fine throughout the garden and the house.

The pieces include:

iPOD Touch 8GB Model A1288 MC086BT/A running iOS 4.1, WiThrottle and WiThrottle Lite
TP Link outdoor wireless access point (TL-WA5210G)
PC running Windows XP, JMRI v2.10 and Lenz LI-USB v3.6
ZTC 511

The next step will probably be to try an Android tablet which is much cheaper than the iPOD. Once I have chosen between the two I will need to buy a few more.

This setup means that I can expand the number of wireless throttles and not worry too much about changing my DCC system because JMRI support a wide range.

7 December 2010

My first attempt to use my ZTC511 and ZTC622 throttles as slaves on my Lenz 100 cab bus failed for some reason which I don't understand.

Comments on the DCCUK yahoo group encouraged me to have another go this morning and everything seems to be working fine. I have set my ZTC511 to work in slave mode with address 7.

I can now use my Lenz 100, ZTC511, ZTC622s and iPOD together. Although the ZTC511 is still restricted to functions 0-8 the ZTC622s will now work functions 0-11 and the LH100 and iPOD handle all of them. It is particularly good being able to label the buttons on the iPOD. That saves trying to remember the number assigned to each function.

19 December 2010

My friend Vic included the following record of a running session in the summer with his Christmas card.

That demonstrates the disadvantages of DCC. We had three trains chasing each other on one circuit with no signalling protection. Our old minds tend to wander after a while and the trains catch up with each other. Even at slow speed my CMX track cleaner pushed by my Heljan class 47 can do a lot of damage to anything in the way.

I am planning to divide this circuit into 3 sections protected by signals. Dead sections after the signals will only be live when the signal is clear. CTI will control the signals automatically when the manual signal boxes are switched out.

I am also experimenting with magnets under any vehicle which might be last in a train. Reed switches in the track will operate CTI sensors so that the number of magnets in a train can be counted. That way a check can be maintained that the train has not split enroute unintentionally.

Implementation of all this will have to wait for better weather but my experiments look promising.

31 January 2011

I have been learning more about JMRI and the points for my hidden sidings can now be operated by JMRI as well as CTI. I have also set up the sidings as routes in JMRI. This means that I can operate the points and routes from my iPOD which is very useful when having to wander into the garage away from the control panel.

I have not decided yet whether to use the MERG decoders instead of CTI control modules on the rest of the 3mm and 7mm layouts.

6 March 2011

I have taken delivery of my first CTI Signalman-IC and 2 Sentries. I plan to use the Signalman to operate the LEDs in my block instruments. I chose the IC version because I think it can also be used to operate relays if required. The Sentries will be used in control panels to detect switches.

14 May 2011

I took delivery of my second iPOD today. I bought it second hand from Cash Generator. I will be interested to see what impact this has on my control system.

Accessory Decoder Upgrade - 21 June 2012

I am using MERG Kit 53 Accessory Decoders for points and signals. For points I am using one pole on a DPDT relay to switch a servo via a MERG Servo4 and the other switches the frog, or a 2nd relay if an additional switch is required. For signals I am switching an opto-isolator which in turn switches a Servo4. There is enough power available from an Accessory Decoder to drive the relays and opto-isolators but I am using a separate power supply to drive the Servo4s.

Using Kit 53 as supplied, if a short occurs the relays return to their normally off state reversing any points which have been set. That is a nuisance especially when stock is sitting on a point which is then changed to normal and causes a further short of its own confusing fault finding.

The alternative Acc5.2-noWDT software does not reset the decoder when the DCC signal is lost. It is available to MERG members at:

http://www.merg.org.uk/forum/viewtopic.php?f=85&t=920&start=25#p5568

I can highly recommend MERG if you are interested in this sort of thing.

I bought a Pickit2 Starter Kit from Rapid and an ICSP18/20A Adapter with ZIF socket from here:

http://www.j1sys.com/icsp-adapters/

to reprogram the PIC supplied in the MERG kit. Maybe one day I'll have a go at some PIC programming myself.

My wiring for the Accessory Decoder is included here: Point Control

Page updated

Google Sites

Report abuse