FRED transmissions

[jasonkw]

I have been trying to monitor FRED signals. I just recently purchased a PRO 106. It shows a transmission but no audio chirp. I have a 200XLT which picks up the chirp just fine. I am assuming there is a setting that needs to be changed. I have searched the forum, but I didn't find an answer (or I missed it).

 

[DPD1]

Hmm... Is there some sort of data skip feature maybe? Have you tried with the squelch all the way off and everything?

 

[jasonkw]

I have tried both search and off for the squelch setting. I also tried turning the squelch knob all the way open. I heard the usual static, but no chirp. AFIAK, the PRO106 does not have data skip. The signal meter shows a close transmission at the same time as I hear it on the 200XLT, but there is no audio.

 

[burner50]

Double check your PL settings and be sure its set for analog CSQ

 

[DaveNF2G]

If you use au mode there might be a delay that is long enough to mute the chirp. Try FM.

 

[jasonkw]

Wirelessly posted (BlackBerry8830/4.5.0.186 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/105)

That's probably it. I had it set to au. Now I have to wait. Most through trains are using DPUs here.

 

[jasonkw]

Thanks for the suggestions. I set the mode to FM and squelch to CTCSS. I am hearing the FREDs now.

 

[acepilot340]

Is this beep how the engineers know that the FRED is working?

 

[jasonkw]

The FRED is transmitting train info to the head of the train. The chirp is the sound of computer data. When heard on a scanner, it indicates a train is nearby.

 

[byndhlptom]

Fred tx

The data sent by the FRED ( or EOT, end of train) is a 1200 bps data stream of I believe 196 bits that has the status of the FRED. It is a pretty short burst of data (aprox 200 mSec)

It is sending the BP (Brake Pipe) air pressure, HVM (High Visibility Marker) status (On/Off), Motion sense (motion/stop), Emergency valve status (on/Off), and a unique EOT ID. This is how the LCU (Locomotive Control unit, or HOT [head of train]) knows which knows what unit to comm with. It also can activate the emergency release vale in an emergency to quicken the application of the brakes.

There are some units that also can help the engineer control braking by allowing the activation of service brake pressure from the rear of the train (ES models).

Also being added to many units is GPS tracking (both with and without phone interfacing) for both inventory control and as an additional "black box" type of monitoring.

They do see a lot of abuse (I have to repair them) , vibration, abuse, we've even received ones w/ bullet holes!

tom

 

[timkilbride]

The data sent by the FRED ( or EOT, end of train) is a 1200 bps data stream of I believe 196 bits that has the status of the FRED. It is a pretty short burst of data (aprox 200 mSec)

It is sending the BP (Brake Pipe) air pressure, HVM (High Visibility Marker) status (On/Off), Motion sense (motion/stop), Emergency valve status (on/Off), and a unique EOT ID. This is how the LCU (Locomotive Control unit, or HOT [head of train]) knows which knows what unit to comm with. It also can activate the emergency release vale in an emergency to quicken the application of the brakes.

There are some units that also can help the engineer control braking by allowing the activation of service brake pressure from the rear of the train (ES models).

Also being added to many units is GPS tracking (both with and without phone interfacing) for both inventory control and as an additional "black box" type of monitoring.

They do see a lot of abuse (I have to repair them) , vibration, abuse, we've even received ones w/ bullet holes!

tom

I thought it was 9600 bps data?

Tim K.

 

[DaveNF2G]

I seem to recall from the dim past that EOT and FRED are two different things.

 

[stevelton]

not my understanding. Ive been railfanning for over 20 years, and when cabooses left, and eots came in, everyone in my local train club just started calling them freds (flashing rear end device). But while I was up in the cab, they still had the black box to receive the info from the fred. But when I went to a different locale, I would hear people refering to them as eots, and have just assumed ever since that weather its fred or eot, they are the same, and different groups of people have theyre own nick name for them.
At one time, me the the railroad buddy I ran around with tried to get e new nickname going for them, but it never caught on.
BOB, Blinking on back, cuz we new a guy named Fred, and didnt really like him so we didnt want to call the eot that.
Steven

 

[byndhlptom]

Fred

I was going from memory, I'll check with my work documentation on the bps rate

Yes, to the best of my knowledge, EOT and FRED refer to the same device. There are probably other, more colorful, acronyms out there for this device.....

They have a thankless job, exposed to the elements, abused by many, high vibration, etc.

That they work as well as they do is almost amazing. They are mounted in probably the worst location to TX a 2wt signal to the Locomotive, around, and the length of trains that are only getting longer....

tom

 

[burner50]

I seem to recall from the dim past that EOT and FRED are two different things.

EOT=End of train device
FRED= Flashing Rear End Device.



Same thing

They have a thankless job, exposed to the elements, abused by many, high vibration, etc.

I've found that if the brace is not placed on a rotating drawbar, they can lay down, and eventually wind up nearly upside down, then they hit a crossing and fly off....

 

[stevelton]

There was a time when we all voiced that we did not want to see the end of the caboose era.
With trains getting longer, more often DPs are pushing on the back, and there is no need for EOT then. Maybe we can start a movement now to save the FRED!
Steven

 

[timkilbride]

A "EOT" could be something simple as a red flag.

A "FRED", as Burner pointed out, is a Flashing Rear End Device. This doesn't necessarily mean its talking to the head end via radio. Some smaller roads may use a red flashing light(real similar to a strobe light housing) powered by two 6v lantern batteries with heavy duty magnets. Another "FRED" is a small magnetic red LED light that can be placed on the rear of the train. I have used all the different EOTs and FREDs listed above. Each one has a different purpose depending what the job is.

There are also one-way "FREDs" too. They transmit all the data from the rear end to the head end, but the head end can't talk back(ARM). I have never dealt with these, but I suppose they are used somewhere.

As far as to what term is used to describe your "marker", each railroad is different. The CN guys in Iowa call them "teleys". <---I don't know if I even spelled that right. Management seems to call them "marker". No matter where you go, you will not see the term used the same.

Tim K.

 

[Allan_Love_Jr]

Union Pacific doesn't use FRED's on the their DPU's. But for some un-Godly reason the BNSF still does.

 

[timkilbride]

Union Pacific doesn't use FRED's on the their DPU's. But for some un-Godly reason the BNSF still does.

The FRED is already in place, or at least with the train, when the train goes back empty in conventional mode.

Tim K.

 

[burner50]

The FRED is already in place, or at least with the train, when the train goes back empty in conventional mode.

Tim K.

UP Does this too, but the EOT is stored inside the nose of the DPU. On some widebody units, you literally cannot fit the EOT on the knuckle... The nose platform is in the way.