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Optimized Digitrax Loconet

asychis@...
 

Optimizing Loconet at the Amarillo Railroad Museum is a very high priority.  We have a large Digitrax-equipped layout that will eventually use a command station and six boosters, around 20 PM42s, numerous UP5s, detectors, etc.  Reading the great information on the internet and this site, we are trying to make sure we have our Loconet up to the highest standards possible.  However, there are still a few nagging questions.

We took to heart Allan Gartner’s Wiring for DCC site, and have ensured that all of components are grounded together.  We prefer to use a heavy ground wire, so we use case attachments on the command station and boosters since this is easier and more secure than using the tiny Digitrax connectors. I will call this the system ground for clarity.

We have also separated the throttles and all other components into a Loconet throttle network and a Loconet booster network, respectively.

Reading Gartner’s site, he suggests strongly that if you use the system ground, you need to cut wires 2 and 5 in the Loconet booster network cable to prevent ground loops.  We have not done this yet, which leads to the current concern.

On another site, rr-cirkits.com, a suggestion is made to cut wires 3 and 4, the Loconet wires on the throttle network, and separating the power supply on the throttle network from the command station, cutting wires 1 and 6 on the throttle network and adding a separate 12-volt power supply connected to the throttle network and the wire 5 ground.  This circuit diagram shows the booster network ground in place. I take it this site either does not recommend or is unfamiliar with Gartner’s separate system ground procedure.  The rr-cirkit.com site also shows a connection between wires 3 and 4 on the throttle network, which I do not understand.

OK, so with all that in mind, is one of these systems better than the other, or can the two be combined, that is, using Gartner’s system ground, removing the booster network ground and adding the separate 12-volt supply to the throttle network? If you can combine the two systems, then the booster network would only have the two Railsync wires; 1 and 6

We are assuming, regardless of the procedure used, that only throttles and respective UP5s be connected to the throttle network and the command station, boosters, PM42s, detection boards (in our case Team Digital Bloc8s), and other devices be connected to the booster network, correct?

Jerry Michels

Kurt Konrath
 

Jerry. Your basis assumptions are correct about common ground, but some units like PM42's I believe should also be connected into the common wire. 

I and most all the people I run with use full six wire Loconet cables.  Never had ground loop problems unless you make full complete circle in the Loconet cables.   Always leave last unit plugged in to one end of the line to deadens the circuit.  If you had a full circle layout or square just don't connect ends together where the come to meet. 

Per standards I have learned from great Digitrax people at two National Train shows, you are correct in having a separate booster and power control Loconet "backbone" to controls all power related items. 

Also having a separate network for throttles is important. 

Have you thought of installing Loconet Repeaters (LNRP's) with each booster?

With our modular setups we have one LNRP with each booster. The power backbone connects all of them and the connect to boosters. 

Also each power district has a matched Throttle district connected to the unprotected side of the LNRP.  

This keeps problems isolated to specific districts as a bad throttle plug on one side won't short the whole layout. 

Make stable system and trouble shooting easier

Kurt Konrath
OK Free-mo



On Nov 23, 2016, at 11:40 PM, asychis@... [WiringForDCC] <WiringForDCC@...> wrote:

 

Optimizing Loconet at the Amarillo Railroad Museum is a very high priority.  We have a large Digitrax-equipped layout that will eventually use a command station and six boosters, around 20 PM42s, numerous UP5s, detectors, etc.  Reading the great information on the internet and this site, we are trying to make sure we have our Loconet up to the highest standards possible.  However, there are still a few nagging questions.

We took to heart Allan Gartner’s Wiring for DCC site, and have ensured that all of components are grounded together.  We prefer to use a heavy ground wire, so we use case attachments on the command station and boosters since this is easier and more secure than using the tiny Digitrax connectors. I will call this the system ground for clarity.

We have also separated the throttles and all other components into a Loconet throttle network and a Loconet booster network, respectively.

Reading Gartner’s site, he suggests strongly that if you use the system ground, you need to cut wires 2 and 5 in the Loconet booster network cable to prevent ground loops.  We have not done this yet, which leads to the current concern.

On another site, rr-cirkits.com, a suggestion is made to cut wires 3 and 4, the Loconet wires on the throttle network, and separating the power supply on the throttle network from the command station, cutting wires 1 and 6 on the throttle network and adding a separate 12-volt power supply connected to the throttle network and the wire 5 ground.  This circuit diagram shows the booster network ground in place. I take it this site either does not recommend or is unfamiliar with Gartner’s separate system ground procedure.  The rr-cirkit.com site also shows a connection between wires 3 and 4 on the throttle network, which I do not understand.

OK, so with all that in mind, is one of these systems better than the other, or can the two be combined, that is, using Gartner’s system ground, removing the booster network ground and adding the separate 12-volt supply to the throttle network? If you can combine the two systems, then the booster network would only have the two Railsync wires; 1 and 6

We are assuming, regardless of the procedure used, that only throttles and respective UP5s be connected to the throttle network and the command station, boosters, PM42s, detection boards (in our case Team Digital Bloc8s), and other devices be connected to the booster network, correct?

Jerry Michels

asychis@...
 

Thanks Kurt,  This is good information.  I am pretty busy getting ready for 20 or so Thanksgiving guests.  I will reply in detail later on.  Thanks again, and Happy Thanksgiving to you and yours.
 
Are you in Oklahoma?
 
Jerry Michels

Kurt Konrath
 

That I am.  In Oklahoma City as a fact

Kurt


On Nov 24, 2016, at 7:37 AM, asychis@... [WiringForDCC] <WiringForDCC@...> wrote:

 

Thanks Kurt,  This is good information.  I am pretty busy getting ready for 20 or so Thanksgiving guests.  I will reply in detail later on.  Thanks again, and Happy Thanksgiving to you and yours.
 
Are you in Oklahoma?
 
Jerry Michels

asychis@...
 

Thanks Kurt.  Since the turkey is now digested, I can write a good reply! We do have a common ground wire running to all devices, including PM42s. We have made sure that the Loconet cables do not form a circle.  Right now we have two cable runs, one for the throttles and one for the boosters and associated devices, such as PM42s, detectors, etc.  So I am confident that we have the correct cable runs.
 
We have not installed LNRPs.  The Digitrax literature is, as usual, pretty thin.  It shows one DCS or DB connected to a string of LNRPs.  So I am not sure what happens with multiple boosters.  It the setup:
 
 
DCS-LNRP-DB-LNRP-DB-LNRP-DB-LNRP and so on with other devices (PM42s, etc.) connected to the output (unprotected) side of the LNRP?
 
So, you live in OKC!  Yo need to make the trek to Amarillo and see our setup sometime.
 
Jerry Michels