I believe this is possible using an m84, using the relay contacts instead of the push buttons.

But the problem becomes, how are you going to rotate the containers to get them to line up with the wagons when loading, or with each other as you stack them when unloading? There will inevitably be some twist in the lifting thread as items are raised and lowered that will cause some rotation of the load as it goes up and down.

Hi John
To drive the 7051 cran in digital poses no problem using a m84 (60842) one output for each dierection of each motor so 4 outputs for the 2 motors plus one output for the solenoid
You may add one sensor (easy) on the gantry top to have a reference in rotation and a delay allows you to stop the rotation where you want


Adding a second sensor is more tricky
- you must add a ring switch on top of the gantry (see above)
- you must add a finger contact in the cabin
See here the inside of the 7051 cabin (where to add the contact

These allow you to pass to an external S88 the position of the hook

I suggest you to read this subject

https://www.marklin-users.net/forum/search#0|5

Here is what I did with another Märklin crane (76510) and 2 sensors (one for translation and one for rotation) with a CS3


Cheers
Jean

Hi Ross
I have used 2 methods:
- events on a CS3 with 2 sensors and delays to stop or start le crane
- XML language in Rocrial with 2 sensors and delays the same way. The difference is a much more accurate positioning thanks to timings in milliseconds
In both cases, the sensors were scanned by S88 on the CS3
Cheers
Jean

Hello all,

Thank you for all of your comments.

I am going to try out my initial considered solution for the crane during this weekend.
You have opened my mind to the idea of feedback control for the crane using s88, which I had not considered but which may be required.
I shall keep you posted after the weekend on how it goes.

USING M83 FOR UNCOUPLER PROCESS

My initial solution for the crane was formed after using the 60832 M83 for an uncoupler process which we were working on.
We were unhappy with the default solution of the uncoupler track in an event.
The uncoupler would activate only for a short period, not long enough to ensure that the train pulls away while leaving the wagons behind.

So I decided to program the M83 to use Mode_1, that means 8 switches with 4 addresses.
A key observation here is that the uncouper is activated by a press of the button, and then it remains active until a second press of the button.
Now, we can hold the uncoupler active while the train pulls away, and then release the uncoupler.
This works very well.

USING M83 FOR CRANE PROCESS

My idea for this weekend is to program the M83 in the same way as we have done for the uncouplers, namely 8 switches with 4 addresses.
So, we can use one M83 for up to 8 switchable functions.
Two functions for rotating the crane, two functions for lifting and lowering the hook, and one function for activating the magnet.

Of course I realise that this has some limitations.
I have not planned the feedback control.
And this method uses track power, which ideally we would prefer not to do.
I think that the M84 can also be programmed to use external power with 8 switches and 4 addresses, so this may also be a solution.

I'll keep you posted !

M83 OPERATING MODES - FOR INFORMATION

CV 79 – Preset Operating Mode
An operating mode can be selected and set for the m83
decoder by means of CV 79 in order to simplify the configuration of the outputs.
By selecting one of these modes, all of the relevant individual CVs are automatically set according to the mode selected.
However, the settings have no effect on the controller so
that here the assignments must be set specially accordingly.

Mode 0 (Value 0) – Standard Mode
In this mode of operation, the decoder occupies 4 addresses. This is the mode on the decoder as delivered from the
factory. It serves to control 4 solenoid mechanisms with end
shutoff features.
-> Turnout or solenoid item
Occupies the address set + 3 more addresses

Mode 1 (Value 1) - 8 Switches, 4 Addresses
In this mode of operation, the decoder occupies 4 addresses. Switching outputs is done by momentary buttons (the
same button for on and off). One output is controlled by the
red momentary button, the green momentary button controls
the second output.
-> 8 Lighting outputs without status indicator.
Occupies the address set + 3 more addresses

Mode 2 (Value 2) - 8 Switches, 8 Addresses
In this mode of operation, the decoder occupies 8 addresses.
Switching outputs is done by means of red-green switches
or a selected symbol. Red switches the output off, green
switches the output on. The brightness of the output can be
set with the dimmer parameter. The period has no function.

Hi John,

Well done.

Once you have finalized the m83 settings can you provide a table of the settings please?

Using a time duration for the crane rotation will be difficult to maintain consistant positions as it is dependant on wear and tear, temperature, lubrication and system response.

For the hook up/down I found that a timed duration was ok as it doesn't need to be too accurate.

I look forward to you results.

Hi John,

Thanks for the update. It seems you have left all output settings to the default once you have set CV79=2.
For each ouptput you can also set the type of switching function, pulse width and period. In this case period isn't used.

For channel 1 are the red wires for the rotation motor?
For channel 2 are the black wires for the hook motor?
The yellow wire would be for the light/magnet function.