JMRI USB interface with NCE Power Cab

[woodone]

Just an up date to this- I just reinstalled the driver and JMRI. I looked at the devise manager and checked the ports and baud rates all were where they were suppose to be. I opened up decoder pro and to a new loco and tried to read- nope- it timed out and in the decoder type box at the bottom it said can’t talk to the command station.??So the next try I changed the cable between the throttle and the PC panel. It now reads the decoder, woooray!  I have not shut it down yet because I had loco I wanted to get out of the way. But so far I think the cable had a bad connection/? I can not figure out how the throttle still was able to operate the loco and I could change CVS with the Power Cab with the other cable ?Who knows? I just know for right now it works.

[carlso]

Way to go Jerry. You ae a real hacksaw !

Be well,
Carl

[John]

way to go . it appears the cable may be the culprit?

[nickelplate759]

If I had a nickel for every time I spent an hour chasing a problem that turned out to be a bad cable or other bad connection I'd have enough nickels to pay for some training on proper diagnostic protocols.

[woodone]

Well I just learned today that the USB interface uses wires #3 & 4 . So when you are using the power cab these wires do not have anything to do with the ability to run a loco (decoder) per say. That’s why it took me so long to figure out the cable is bad.

[peteski]

Well I just learned today that the USB interface uses wires #3 & 4 . So when you are using the power cab these wires do not have anything to do with the ability to run a loco (decoder) per say. That’s why it took me so long to figure out the cable is bad.

Now that you mentioned, it makes perfect sense. Power Cab uses a 6-conductor cable.  When used as Power Cab it only uses 4 of the 6 conductors:  Power and Ground pair feeding it, then another pair supplying the DCC track power to the track (since the handheld also contains its own command station and booster inside).

When that Power Cab throttle is used as Pro Cab, it also uses 4 of the 6 conductors:  the same pair used for power and ground feeding it, then the other pair (wire 3 and 4) which are serial bus communication pair which communicates with the command station.  The DCC track power pair is not used.

When that handheld unit is used as Power Cab, while also using USB, then all 6 wires are utilized.  I don't have the USB interface for my Power Cab so I never really thought about all this until you pointed that out.

[John]

Well I just learned today that the USB interface uses wires #3 & 4 . So when you are using the power cab these wires do not have anything to do with the ability to run a loco (decoder) per say. That’s why it took me so long to figure out the cable is bad.

Good on you for sticking with this problem .. I'm glad you found a resolution .. congrats

[TiogaTracks]

Thanks for your persistence with this solution!  I followed this with interest, as I’m hoping to use some NCE hardware I already have as I upgrade to JMRI.  I feel a bit more confident now, thanks again!

-Steven