Cab-1L Remote Direction

I believe this is correct.

The CAB-1L is BI-Directional with the BASE1-L and Legacy Command Base.

Here are the description letters of the CAB-1L and BASE1-L from Lionel to the FCC for approval. Notice they describe the CAB-1L as a transceiver and specifically mention bi-directional communication capability. Quoted from the BASE-1L letter: The BASE-1L Command Base uses a Texas Instruments transceiver which gives the command base
bi-directional communication capability. And from the CAB-1L letter: The CAB-1L remote controller is also capable of receiving information packets from the
command base. We know the CAB-2 and Legacy Command Base have bi-directional communications. the CAB-1L is capable of bi-directional communications. Does the CAB-1L actually use the bi-directional communications capability? These are from the FCC website.

It appears the BASE-1L does actually communicate with the CAB-1L bi-directionally. Here are the FCC test reports. If you are looking for the 455 kHz transmission from the base there is a sentence that explains that it is considered a carrier current communications on page 8 of the BASE1-L test document. These documents are from the FCC website.

Of course if you have a spectrum analyzer and an antenna you could actually test the CAB-1L and BASE1-L and see if there are signals going both ways.

@PennsyTurbine posted:

Of course if you have a spectrum analyzer and an antenna you could actually test the CAB-1L and BASE1-L and see if there are signals going both ways.

I have the S/A but it's a bit more complicated when you go to actually do the measurement. You can see the BASE transmitting after receiving a command from the CAB-1L..

However, I'm assuming the commands from the CAB-1L are exciting the same firmware in the BASE as if I was holding a Legacy remote (why would you have two protocols?), so just because the BASE is still sending out packets in the reverse direction doesn't mean the CAB-1L is actually receiving them or using them for anything. The CAB-1L has no outputs of any kind as far as I can tell, the beeps have the same behavior wither the BASE is on or off and there's no LEDs or anything so it's unclear what the purpose of using the reverse link would even be...

Just to jump in here remember when selecting a channel on the Cab-1L that it does beep once when connected to a base and 3 times when it detects no base. While I may be wrong this may imply some sort of two way communication

@Adrian! posted:

The CAB-1L has no outputs of any kind as far as I can tell, the beeps have the same behavior wither the BASE is on or off and there's no LEDs or anything so it's unclear what the purpose of using the reverse link would even be...

Personally, I'd be a little surprised if the CAB1L is using the reverse channel, as you say, what would it be doing with it?

I thought the CAB-1L was a transmit only device. The FCC test reports clearly show that both the CAB-1L and BASE-1L are both transmit and receive devices. They have the capability to transmit and receive. Why design the BASE-!L to transmit and the CAB-1L to receive if it is not being used in that way. I'm sure the Legacy Command Base treats the the CAB-2 and CAB-1L the same as Adrian suggests. So we seem to have a puzzle here. I would be surprised if Lionel went to all the trouble of having the BASE-1L transmit and the CAB-1L receive if it did not serve some purpose.

Adrian would you happen to have a BASE-1L? If so you could see if it is transmitting. If the reverse communications is not used, then it should not be transmitting?

Adrain when you said you said the "base" is transmitting, I am guessing you are using the Legacy Command Base?

I did not know the Legacy Command Base re-transmits every command it receives over 2.4 GHz. I knew it re-sent each command over the serial port. Why would it re-transmit every CAB-2 (or CAB-1L) remote command?

Attached is the operational description of the Legacy Command Base (which is referred to as a BASE2) from the FCC website. From the description you can see that the Legacy Command Base does receive and transmit at 2.4 GHz. Or course it also sends out the 455 KHz track signal.

Lionel uses the Texas Instruments Chipcon CC2500 Transceiver IC in the Legacy Command Base, Base-1L, CAB-2 remote and CAB-1L remote for the 2.4 GHz signal. The Radio Board is Lionel 691-RAD2-E00 and the newer 691-RAD2-F00. You can clearly see the CC2500 on the chip on the PCB. A full set of technical documents is on the Texas Instruments website www.TI.com for the Chipcon CC2500. Application Note AN048 shows the Fractus antenna that Lionel uses. The picture of the 691-RAD2-F00 is from Lionel's website in the parts section. Since the CAB-2 and BASE-2 appear to use bi-directional communications, the CAB-1L most likely does the same. The CC2500 IC most likely implements a send, did you get that, no resend type protocol for the CAB-2 and CAB-1L to the command base. The second photo is from the FCC website showing the inside of the Lionel CAB-1L with the radio board 691-RAD2-E00 and at the top in blue is the Fractus antenna.