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diff --git a/docs/tutorial.rst b/docs/tutorial.rst index d099d57..b44cc6a 100644 --- a/docs/tutorial.rst +++ b/docs/tutorial.rst @@ -22,24 +22,30 @@ Let's go *in medias res* and have a look at a simple example:: This example already shows the two main design goals of PyVISA: preferring simplicity over generality, and doing it the object-oriented way. -After importing ``visa``, we create a ``ResourceManager`` object. If called without -arguments, PyVISA will use the default backend (NI) which tries to find the -VISA shared library for you. You can check, the location of the shared library -used simply by: +After importing ``visa``, we create a ``ResourceManager`` object. If called +without arguments, PyVISA will use the default backend (NI) which tries to find +the VISA shared library for you. You can check, the location of the shared +library used simply by: >>> print(rm) <ResourceManager('/path/to/visa.so')> -.. note:: In some cases, PyVISA is not able to find the library for you - resulting in an ``OSError``. To fix it, find the library path - yourself and pass it to the ResourceManager constructor. - You can also specify it in a configuration file as discussed - in :ref:`configuring`. +.. note:: + + In some cases, PyVISA is not able to find the library for you resulting in + an ``OSError``. To fix it, find the library path yourself and pass it to + the ResourceManager constructor. You can also specify it in a configuration + file as discussed in :ref:`configuring`. Once that you have a ``ResourceManager``, you can list the available resources using the ``list_resources`` method. The output is a tuple listing the -:ref:`resource_names`. +:ref:`resource_names`. You can use a dedicated regular expression syntax to +filter the instruments discovered by this method. The syntax is described in +details in :py:meth:`~pyvisa.highlevel.ResourceManager.list_resources`. The +default value is '?*::INSTR' which means that by default only instrument +whose resource name ends with '::INSTR' (in particular USB RAW resources and +TCPIP SOCKET resources are not listed). In this case, there is a GPIB instrument with instrument number 14, so you ask the ``ResourceManager`` to open "'GPIB0::14::INSTR'" and assign the returned @@ -51,14 +57,15 @@ Notice ``open_resource`` has given you an instance of ``GPIBInstrument`` class >>> print(my_instrument) <GPIBInstrument('GPIB::14')> -There many ``Resource`` subclasses representing the different types of resources, but -you do not have to worry as the ``ResourceManager`` will provide you with the appropiate -class. You can check the methods and attributes of each class in the :ref:`api_resources` +There many ``Resource`` subclasses representing the different types of +resources, but you do not have to worry as the ``ResourceManager`` will provide +you with the appropriate class. You can check the methods and attributes of +each class in the :ref:`api_resources` Then, you query the device with the following message: ``'\*IDN?'``. Which is the standard GPIB message for "what are you?" or -- in some cases -- -"what's on your display at the moment?". ``query`` is a short form for a ``write`` -operation to send a message, followed by a ``read``. +"what's on your display at the moment?". ``query`` is a short form for a +``write`` operation to send a message, followed by a ``read``. So:: @@ -87,5 +94,3 @@ one ``query()`` call. Thus, the above source code is equivalent to:: print(itc4.query("V")) It couldn't be simpler. - - |