PC Controlling

[Anonymous]

Hi all!
I'm interested in how many trains I can control by PC.
As I know, each train is connected to PC through COM Port or LPT Port.
So,if I have only two COM Ports, does that mean that I can not simultaneously connect to my PC more than two Trains ?

Can you describe me how all this connection happens???
Thaks,
Gvido.

[SpaceMouse]

I don't know who train controlling software works, but it is not unreasonable to assume that you could contol an unlimintied number of trains through a com port ,or an ethernet connection, etc. depepnding on how your computer interfaces with your DCC system, software program etc.

When I think about it, it would cool to have several trains go out and back while you sort them in a yard, or take a train around the track on your own, trying to drop cars off in traffic.

[Anonymous]

Thaks for aswer.

But it is still incomprehensible ,does one com port respond to one connected train ?

[Jetrock]

No--normally computer-based control systems use a carrier signal that addresses a receiver chip in each locomotive. Remember, the control software is attached to the track, not the trains.

Thus, the computer acts as a director, telling each train in its control what to do. A system like this sends power to all the track at once, with a carrier signal that the decoder in each locomotive can interpret. Each loco has a unique identifier--so the computer can say (for example): "Engine 1, increase speed to 50% of full power. Engine 2, slow to a stop. Engine 3, wait in the passing siding until Engine 1 has passed, then proceed on clear signal."

There are older homebrewed systems that you plugged into an Apple II, but nowadays digital command control typically means a DCC (Digital Command Control) system--you'd plug your PC into the DCC controller (using something like a USB cable or network cable, I assume) and the computer tells the DCC controller what to tell the trains.

[Anonymous]

But how computer differs locos?
Lets say that I have 3 identical locos,each with address ,lets say, "3"(Digitrax).(Each loco has it's own address).
I can give them IDs e.g. "Loco1","Loco2","Loco3".
But after that,how can be sure, that sending command to "Loco2" , it wasn't recieved by two other locos?

[simon1966]

I have a PC connected to my Digitrax Zephyr via a serial port. I run the JMRI Decoderpro application (Free download, see the current thread on "12 years of experience with DCC" by J. Furgate). Decoderpro has a throttle function, where you can create a virtual on screen throttle. I have only ever made 3 at the most, but I don't beleive that there is a limit. The limitation would most likely be the number of throttles the DCC command station can handle. So in answer to your question, One serial interface can equal many locomotives.

[simon1966]

QUOTE: Originally posted by Gvido

But how computer differs locos?
Lets say that I have 3 identical locos,each with address ,lets say, "3"(Digitrax).(Each loco has it's own address).
I can give them IDs e.g. "Loco1","Loco2","Loco3".
But after that,how can be sure, that sending command to "Loco2" , it wasn't recieved by two other locos?

One of the first things you should do with a new DCC installation or DCC equipped locomotive is to asign it a unique address. The communication between DCC system and locomotive depends on the unique address. If you have 3 identical locomotives all with the same DCC address, then all 3 will respond to the commands at the same time that are sent to that address. This is imaterial of a PC connection, the same would occur from commands sent from your DCC throttles and command station.

[Anonymous]

Thanks a lot!!
So,by changing unique address of each loco, I can distingui***hem from each other,even if they are identical!

[simon1966]

QUOTE: Originally posted by Gvido

Thanks a lot!!
So,by changing unique address of each loco, I can distingui***hem from each other,even if they are identical!

Correct. Most DCC systems support 2 or 4 digit address. I prefer to use a 4 digit address as I can then use the locomotive road number for the DCC address. For example, I have a BLI Wabash E7 road number 1001. When it was new it had the often defualt DCC address of 03. The first thing I did was to put it on my programming track and reprogram the address to 1001 to match the road number. The advantage of this, is that you have to remember the DCC address, so it is easier if it matches the lococmotive number. If you have more than one loco with the same road number then you will have to have another method to select the DCC address.

[Anonymous]

So addionally I'll have to consider 4 digit address...
Wow....It means that I'll have to use CVs...

Ok. Thanks a lot,Simon!
I'll take into account your remark!!

Is there any addional information concerning this subject?

[simon1966]

If you learn nothing else, learn how to change the address of the locomotive. It will likely be well described in the documentation.

Have a read of the J. Furgate clinic linked below. It is a great introduction to DCC

http://www.trains.com/community/forum/topic.asp?TOPIC_ID=36389

[Anonymous]

As I've noticed in DecoderPro. The switching between 2 and 4 digit addressing is implemented by sending a coresponding CV to Loco.