Saving a session whilst NOT saving driving progress?

With the introduction of the UDS Unified Driver Surveyor feature, I have come across this problem.
If I am driving in a route, and find something that needs changing in a session layer - for example the position of a trackmark - I will then exit driver into surveyor, make the changes and save and then either switch back to driver and continue or exit.
But next time I go to edit session, the position of the train is already on (or past) the location where I found that a change was needed.
How can I save changes to a session layer, whilst also saving the starting position of trains?

You don't save the session when in driver mode only the route. The session will always save at the point you are at in driver mode and unless you change the session name it will replace the original session. Only changes to the route layers should be done when in driver mode if you want to keep the original positions of trains. If you do need to alter something that is in the session layer do it in the route layer and then when you open the original session for edit you can move it over to the session layer.

stagecoach said:

You don't save the session when in driver mode only the route. The session will always save at the point you are at in driver mode and unless you change the session name it will replace the original session. Only changes to the route layers should be done when in driver mode if you want to keep the original positions of trains. If you do need to alter something that is in the session layer do it in the route layer and then when you open the original session for edit you can move it over to the session layer.

Click to expand...

Thanks Stagecoach. That took a couple of readings to get the hang of! So, in my example of needing to move a session layer trackmark, I would
1- Switch from driver to surveyor
2- Ensure I am editing route layer
3- Add new trackmark in correct position
4- Exit and save route, do not overwrite session
5- Open original session in route/session/edit, not from driver.
6- Find new trackmark, edit properties to be in session layer
7- Delete old trackmark from session layer
8- Alter driver instructions so train is directed to new trackmark.
9- Save route, this time overwrite session.

Not exactly a smooth seamless process. But I can appreciate it will be very useful for altering the underlying route.
For altering session details, it will be neccessary to follow the previous proceedure.

Manu thanks for your clarification.

Anything in the route layer or below it will always save to the route. Anything in the session layer or below will save to the session. You can move layers between the route and session and vice versa.

stagecoach said:

Anything in the route layer or below it will always save to the route. Anything in the session layer or below will save to the session. You can move layers between the route and session and vice versa.

Click to expand...

A minor rewriting.

Anything in the Route Layers will always save to the route.
Anything in the Session Layers will always save to the session. Session Layers are never saved in the route.

There is a Trainz Wiki Page on using the UDS interface and how to avoid the problem of saving the consists progress during the running of a session. The page is at https://online.ts2009.com/mediaWiki/index.php/How_to_Use_the_UDS_Interface