The unit on the left is a VHF model used for the live audio feed and the other two are used for ATCS monitoring. On the second shelf is the pre-amps, splitters, etc as well as the power supply for all the equipment. The bottom shelf is used for storage.
RWMON ATCS monitor for Raspberry Pi; RWMON ATCS monitor for Windows. The Pi version is best for setting up a monitoring station and easiest to use. The Windows version is more for experimenting with and is not being updated.
Able software called “ATCS Monitor” it is possible to decode this information and display it. Monitoring these signals is equivalent to monitoring the railroad personnel’s voice communications on a scanner. As with voice, we can only hear as far as our antenna locations will allow. When the stations is blue, con-trol messages sent from.

Advanced Train Control System (ATCSMon) F. Stout Goodyear, AZ Page 1 6/15/2011 Authors Note This document is intended to assist people new to the ATCS monitor and the associated Yahoo Group to get started using ATCSMon. A great deal of what is presented below exists on the Yahoo Group but may be a bit confusing for new people. Number Railroad; 022: Atchison Topeka Santa Fe: 340: ATCS Shared Network: 400: Kansas City Southern Railway Company: 721: Southern Pacific Transportation Company.

Welcome the ATCS (Advanced Train Control System) page at AlabamaRailfan.com.The CSX S&NA (South and North Alabama) North Subdivision extends from Birmingham, AL to Nashville, TN.CSX has trackage rights over the Tennessee River in Decatur, AL via the Norfolk Southern. TheS&NA North ATCS feed originates in Decatur, AL and covers roughly 50 miles of CSX and the threeMCPs used by the NS to control the interlocking in Decatur (most of the rest of the NS through northAlabama is Track Warrant Control with only the newest sidings/interlockings being converted to ATCS).

Check out the CarPuter installation I did of a desktop PC in the 2000 Chrysler Concorde we used to own:http://www.alabamarailfan.com/atcs/carputer.php.We have a new vehicle now, so I will be starting over, but this made a great ATCS monitoring system whileI had it running! :)

Under normal conditions, the feed is receiving message packets from two CSX BCPs. BCP ID 45957, whichis located near Falkville, AL, is approximately 18.8 miles south of the server location. BCP ID 46020,which is located near Athens, AL is approximately 16 miles north of the server location. The twoBCPs typically cover from N Ardmore to N Holmes Gap, a distance of about 50 miles. The NorfolkSouthern MCPs that control the interlocking through Decatur are about three miles north/northwestof the server location. The server typically covers 12 CSX MCPs and the 3 NS MCPs. Typical errorrates are <20% overall with indication sequence errors ranging 2% - 9% on most MCPs covered.

You can also listen to the action 'almost live' from the live scanner page!Although the live scanner audio is delayed about 2 - 3 minutes, it does cover most of the area highlighted by the ATCS server.

Atcs Monitor Virginia

This capture of the dispatcher display from the CSX S&NA North Sub highlights some of the action.The above image shows CSX local M781 lined from the siding at Oakworth Yard, through the NS interlocking acrossthe Tennessee River. CSX Q688 is approaching N Holmes Gap and is lined all the way to the Decatur HO signal.The small DS controlled spur at N Holmes Gap is a pusher pocket to help CSX trains over the mountain betweenN Holmes Gap and M Holmes Gap.

Occasionally, DX conditions will be right that the server will show packets from many more locations.I have seen CSX BCPs 46018 and 45845 during such occurrences. I suspect that the 46018 BCP may belocated somewhere south of Nashville, TN and that the 45845 BCP is located somewhere on the CSXChattanooga Sub, as you will generally see MCPs from this sub when the 45845 BCP is coming in. Eventhough there is a large hill/mountain (referred to by CSX as Sand Mountain) between N Holmes Gap andM Holmes Gap, DX conditions will often pull in packets from MCPs located south of Holmes Gap and itis not uncommon to get a few MCPs from the Boyles Terminal in Birmingham, AL.

The north end of the S&NA North Sub is the Nashville Terminal Sub. Be sure to check out Scott andBrandon Baxter's Nashville Terminal Sub ATCS Feed. You can find info about their feed from the messagearchives at the ATCSMon group at Yahoo.com!

I would like to extend my sincerest gratitude to the people that helped make this server possible:Chris Guss, Mark Landgraf, Richard Musgrove, Jim Groenke, Rob Jordan and especially Larry Gabriel and Steve Miller! : )

Download Server Monitoring Kit: http://finance.groups.yahoo.com/group/ATCS_Monitor/files/Data Files/CSX/Nashville Div/S&NA North Sub/csx_s&na_north_monitoring_kit.zip
Current Server Addresses:
alabamarailfan.dyndns.org:4800 - CSX BCP Data
alabamarailfan.dyndns.org:4801 - Norfolk Southern MCP Data

ATCS Monitoring - maintained by the
National Railway Historical Society (NRHS) - Harrisburg Chapter

Atcs Monitor Railroad

The Harrisburg Chapter of the NRHS maintains a network of ATCS receivers and internet servers covering much of the NS Harrisburg Division. This system allows railroad enthusiasts to view train locations, switch and signal settings and train routing on a graphical display in much the same way as a railroad dispatcher. Using a freeware (no cost) program called “ATCS Monitor” users log into the Harrisburg NRHS’s router to receive the data in much the same way as one would receive railroad radio transmissions via an Internet scanner feed.

What is ATCS?
ATCS is the Advanced Train Control System and is a form of 'radio code line' now being used by the railroads. Previously, signal, switch and track indications and controls were done by way of the wayside copper wires. Later, railroads began using fiber optic cables for this purpose. However, there have been on-going reliability issues. Copper and fiber on poles is subject to wind, ice, lightning and other weather effects. Underground it’s subject to lightning, washouts and back hoes. (Yes, lightning is still a problem underground)! One failure in one location could affect a dozen or more interlockings. To deal with this, ATCS radio code line was developed. By using digital UHF radio, ATCS eliminates the physical connectivity that hampered the signaling systems in the past.

How is ATCS Useful to Railroad Enthusiasts?
ATCS radio signals are NOT encrypted which makes them fair game for anyone with the right equipment to receive. Everyone asks the question, “Is this legal?” The answer is a definite YES! Just as there is no prohibition against receiving railroad voice communications, there is also no prohibition against receiving railroad ATCS signals. As a result, technically oriented railroad buffs formed yet another off-shoot of our hobby: ATCS monitoring. If you have the right type of receiver and freeware software (written by Dave Houy), you can receive the ATCS radio signals and display the information on a computer screen in much the same way as it would appear on a railroad dispatcher's display.

The biggest limitation to receiving ATCS radio signals is that they are in the 900 MHz region. This makes them nearly line-of-sight. The signals are easily blocked by hills, buildings and even heavy vegetation. The railroads solve this problem by placing their equipment on high mountains and/or tall towers. Their high locations give them a clear, line-of-sight 'view' in all directions for many, many miles. Most railfans don't have that advantage. As a result, the typical railfan only has ATCS radio reception for a few miles of railroad in any direction.

Railfans work around this problem by pooling their resources and tying their receivers together by way of the internet. The railroads have one site that covers many, many interlockings. Railroad buffs have many sites, each of which only covers only a few interlockings. However, when you combine the reception of