The starting in wrong direction is a known behaviour with some lok decoders. But usually it gets in sync. after the first reverse command.

The 6090 doesn't know about "absolute direction" - if it's out of sync, it will stay out of sync even if you reverse the direction (because both decoder and controller reverse the direction at the same time).

IIRC the behaviour described here is the normal behaviour for a 6090x decoder.
So it's a progress that you can synchronize loco and controller by reversing the direction.

Yes, in my case they get sync after a reverse command from IB knob, but not from the PC control.

I realize I have forgotten to thank for the answers above!

efel

Hi,

Then that means that the direction bit is of no use for the 6090x? It behaves exactly as a "flip flop", like with the old Mota format?

Thanks for your post, Tom.

I had misunderstood your previous answers. Now it's clear.

But there is still a question, for I can resynchronize the IB and the decoder by pushing the IB knob, what I understand now, but impossible by changing direction using the PC.

Fred

Thanks.

What I wonder is how our friends who use IB with an automatic PC program manage that problem. In fact a loco starting in bad direction in a shadow station is not acceptable.

In my case, I didn't see the problem before, as I used the program of my 6051 to control my IB. 6051 doesn't know absolute direction, so, before starting the automatic play, I had to set in the 6021, and later the IB, the direction of the locos that have to run backwards.

I thought that IB controlled now with P50X protocol, that knows absolute direction, would have avoid me that.

Fred

Hi,
Yes, I will try to morrow.
In the meantime, I'd like to share with you and other experts of this forum, the strange thing I observed.

1st experiment:
1-A first game is stopped with the locos backward, speed 0. (The IB option is : no memory.)
2-The IB is switched OFF, but the connection with the PC stays alive.
3- The IB is switched ON, as well as the booster (home made) to the track.
4- A PC command : speed 1, backward, is sent to the IB.
5-> We get then the behaviour described in the firs post: Loco runs forward instead, and stays non-synchrone after several direction changes from the PC.

2nd experiment:
1- and -2 as above
3-The IB is switch ON, but the booster is OFF: Tracks are not fed by the digital signal.
4- A PC command : speed 1 , backward is sent to the IB.
5- booster ON
6-The loco runs backward and stays synchrone.

Then it seems that the problem comes from the signal sent by the IB at power ON, that disrupts the decoder. On the other hand, the next signals sent by the IB -controlled by PC- are OK : we just have to avoid that the decoder receives the very first signal.

(there is an IB option that allows to change that very first signal (Mota, DCC..). I'll try to change it to morrow)
edit: done. Changing that option (907) does not modify anything.

Fred

Edited by user 25 February 2010 10:49:06(UTC)  | Reason: Not specified