How to start a Device Server?

Hello everyone,

I'm quite new in programming and a total newbie in Tango, so forgive me if my question is straightforward.
My setup is: Windows 10, tango 9.3.3, PyTango 9.3.2 and Python 3.6.8. I have also installed Taurus.
I have successfully installed Tango and have the TangoTest up and running. My problem is when I try to run the PowerSupply server from the PyTango documentation (https://pytango.readthedocs.io/en/stable/quicktour.html). I register the device server in Jive but I don’t know how to start the server. I try to run the “python power_supply.py test” command but there is no response.
In Jive the Device Info shows this:

- Device Info —————————————-

No IOR found in database for test/power_supply/1
(Maybe, the device has never been exported…)
Server: PowerSupply/test
Exported: false
last_exported: ?
last_unexported: ?

- Polling Status ————————————-

Desc -> test/power_supply/1 Not Exported !
Reason -> TangoApi_DEVICE_NOT_EXPORTED
Origin -> Connection(test/power_supply/1)
Desc -> Cannot import test/power_supply/1
Reason -> TangoApi_CANNOT_IMPORT_DEVICE
Origin -> Connection.build_connection(test/power_supply/1)

So from my understanding, do I need an executable to be exported? And to put it in the same folder I have the TangoTest? If so, how is an executable for the device server being created?

Thank you
Hi Evaki.

The installed packages you have sound good (https://www.tango-controls.org/community/forum/c/general/development/how-to-start-a-device-server/?page=1#post-4448).

1. What is the output when you run: python power_supply.py test?
2. What is the output when you run: python -c "import tango; print(tango.utils.info())"

Regards,
Anton
Hi Anton,

As I said, I am a newbie and it is only appropriate that I found what I was doing wrong after I posted my question. I just hadn't activated my venv when running the command in cmd. (Although I had tried it in VS Code too without luck). So anyways, in case it helps anybody else the answers to your questions are:

1.
(.venv) C:\PythonProj\TTtest>python power_supply.py test
Unknown exception while trying to fill database cache…
Ready to accept request

2.
PyTango 9.3.1 (9, 3, 1)
PyTango compiled with:
Python : 3.6.8
Tango : 9.3.3
Boost : 1.70.0

PyTango runtime is:
Python : 3.6.8
Numpy : 1.19.3
Tango : 9.3.3
Boost : 0.0.0

Thank you again!
Okay, great!

(And now you are less of a "newbie"!)
Hi Evaki,

can you tell me which instructions you followed to install Tango + PyTango on Windows? I am trying to do the same and cannot find the instructions.

Andy
Hi Andy,

I mainly used this for Tango https://tango-controls.readthedocs.io/en/9.2.5/getting-started/installation/tango-on-windows.html

I had a problem with creating/starting the db and I used this workaround https://github.com/tango-controls/TangoDatabase/issues/16

As for PyTango I first installed all the prerequisites as they appear here https://pypi.org/project/pytango/
and then followed the instructions from the pytango website https://pytango.readthedocs.io/en/stable/start.html#getting-started

Hope they help you.
Eva
Eva,

thanks a lot! I will try them.

Andy
 
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