Final tests:
For 3.6.0-beta2(.post3) all relevant data-types (float,int,bool,string) worked as expected.
For 3.5.4 with dsf-python-3.5.0 setting string-data and accessing it via "echo ..." also works.
So issue solved for me - merci!
Thx @all for their support to answer questions and find/solve issues!
@AndyE3D @chrishamm thanks for the investigations and the fixes.
Did a quick test, stayed with 3.6.0-beta2 and updated dsy-python to 3.6.0-b2.post3:
-> No exception/exit anymore
-> String-values are correctly set via set_plugin_data
-> Object model plugin variables disappear (only last one modified is visible), accessing them via 'echo ..." works
Reloading the OM-plugin page via browser reload also brings back all values.
Will test tomorrow if using non-string values also works for me and also test 3.5.4 again.
Thanks for your help, have a good evening!
@chrishamm I was using stable 3.5.4
Tried unstable 3.6.0-beta2 tonite and got a different behaviour, the connection was closed by the server with this error "Closing connection: Internal Server Exception" when calling set_plugin_data.
I tried to call the function with a wrong key-name and/or wrong plugin-id, but this didn't change anything.
The log with debug enabled looks like:
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] IPC#62: Granting full DSF permissions to external plugin
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] Command processor added for IPC#62
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] IPC#62: Received command WriteMessage
Dec 09 23:44:01 duetpi DuetControlServer[725]: [info] [IOExample]: IO [auto:True; inputs:True,False,False,True; outputs:True,False,False,False]
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] Got new connection IPC#63, checking permissions...
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] IPC#63: Granting full DSF permissions to external plugin
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] IPC#62: Connection closed
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] Command processor added for IPC#63
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] IPC#63: Received command WriteMessage
Dec 09 23:44:01 duetpi DuetControlServer[725]: [info] [IOExample]: Closing connection: Internal Server Exception
Dec 09 23:44:01 duetpi DuetControlServer[725]: [debug] IPC#63: Connection closed
Dec 09 23:44:01 duetpi DuetPluginService[1702]: [info] Plugin IOExample: Process has been stopped with exit code 0
Calling the function ('set_plugin_data("IOExample", "output0", 1)') with a non-string value gives a different error:
"Closing connection: value must be a string"
Anything else I can test ... ?
So with the usual fiddling around I was able to prepare a test-configuration.
Everything works as expected except one thing: updating the plugin-data via "set_plugin_data".
I declared 4 inputs and 4 outputs in the plugins plugin.json description file. After installing the plugin the object-model looks like this:
Once I modified the plugins data for a single input with this code:
if gOutputs[i]:
plugin_update_connection.set_plugin_data("IOExample", "output{0}".format(i),"1")
else:
plugin_update_connection.set_plugin_data("IOExample", "output{0}".format(i),"0")
All the data properties/values are lost and only the last one modified remains:
I tried to lock/unlock the object-model and also to update all 4 inputs in a for-loops, didn't work too...
@chrishamm any idea what is causing this?
@chrishamm perfect! That was the detail I was searching for 
I will prepare a test-setup with an arduino and some buttons/LEDs to see how it works.
Thanks for your quick help @dc42 and @chrishamm!
@dc42 thanks for your quick reply.
The inputs I am referring to are not on the Duet, they are on an extra 'standalone' board.
But I need to handle some of these inputs in Duet-Macros to execute axis-motions depending on the inputs(-states).
So I would like to update the input-state via DSF (C#- or python), e.g. I would update their value twice per second with a call to 'perform_simple_code("set global.var_name=value")' for every input.
Can this cause performance-issues when a nc-job is running?
Regards,
Reiner
Good Evening,
we plan a setup with a Duet3 Mini5+ and a RPi-5 in SBC mode.
We also want to use additional (most of them digital) inputs from an external uC-Board (we design/implement ourselves). These inputs/values will be used in different macros on the Duet-Board.
As far as I understood, it is not possible to publish/modify global variables of the ObjectModel directly, if the systems runs in SPI (https://forum.duet3d.com/topic/31248/modify-a-global-variable-value).
So possible ways to go are:
a) write a C#/Python-Daemon who periodically pushes the input-states via a simple NC-command to the board ("set global.my_input=...")
b) write a NC-filter-daemon to intercept user-defined M-Codes to query the inputs (not sure if this will work / if NC-macros can parse/handle the answers from the M-codes correctly).
c) modify our uC-Board to support Duet's CAN-Bus (like the Sammy-C21) and publish relevant inputs over CAN
I would prefer solution a) or b).
May I run into other issues doing this or is there a better, more elegant solution for my problem?
Thanks and regards,
Reiner