Resource Manager¶
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class
pyvisa.highlevel.
ResourceInfo
(interface_type, interface_board_number, resource_class, resource_name, alias)¶ Resource extended information
Named tuple with information about a resource. Returned by some
ResourceManager
methods.- Interface_type
Interface type of the given resource string.
pyvisa.constants.InterfaceType
- Interface_board_number
Board number of the interface of the given resource string. We allow None since serial resources may not sometimes be easily described by a single number in particular on Linux system.
- Resource_class
Specifies the resource class (for example, “INSTR”) of the given resource string.
- Resource_name
This is the expanded version of the given resource string. The format should be similar to the VISA-defined canonical resource name.
- Alias
Specifies the user-defined alias for the given resource string.
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class
pyvisa.highlevel.
ResourceManager
(visa_library: Union[str, pyvisa.highlevel.VisaLibraryBase] = '')[source]¶ VISA Resource Manager.
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property
last_status
¶ Last status code returned for an operation with this Resource Manager.
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list_resources
(query: str = '?*::INSTR') → Tuple[str, …][source]¶ Return a tuple of all connected devices matching query.
Notes
The query uses the VISA Resource Regular Expression syntax - which is not the same as the Python regular expression syntax. (see below)
The VISA Resource Regular Expression syntax is defined in the VISA Library specification: http://www.ivifoundation.org/docs/vpp43.pdf
Symbol Meaning ———- ———-
? Matches any one character.
- Makes the character that follows it an ordinary character
instead of special character. For example, when a question mark follows a backslash (?), it matches the ? character instead of any one character.
- [list] Matches any one character from the enclosed list. You can
use a hyphen to match a range of characters.
- [^list] Matches any character not in the enclosed list. You can use
a hyphen to match a range of characters.
Matches 0 or more occurrences of the preceding character or expression.
Matches 1 or more occurrences of the preceding character or expression.
- Exp|exp Matches either the preceding or following expression. The or
operator | matches the entire expression that precedes or follows it and not just the character that precedes or follows it. For example, VXI|GPIB means (VXI)|(GPIB), not VX(I|G)PIB.
(exp) Grouping characters or expressions.
Thus the default query, ‘?*::INSTR’, matches any sequences of characters ending ending with ‘::INSTR’.
On some platforms, devices that are already open are not returned.
-
list_resources_info
(query: str = '?*::INSTR') → Dict[str, pyvisa.highlevel.ResourceInfo][source]¶ Get extended information about all connected devices matching query.
For details of the VISA Resource Regular Expression syntax used in query, refer to list_resources().
- Returns
Mapping of resource name to ResourceInfo
- Return type
Dict[str, ResourceInfo]
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open_bare_resource
(resource_name: str, access_mode: pyvisa.constants.AccessModes = <AccessModes.no_lock: 0>, open_timeout: int = 0) → Tuple[NewType.<locals>.new_type, pyvisa.constants.StatusCode][source]¶ Open the specified resource without wrapping into a class.
- Parameters
resource_name (str) – Name or alias of the resource to open.
access_mode (constants.AccessModes, optional) – Specifies the mode by which the resource is to be accessed, by default constants.AccessModes.no_lock
open_timeout (int, optional) – If the
access_mode
parameter requests a lock, then this parameter specifies the absolute time period (in milliseconds) that the resource waits to get unlocked before this operation returns an error, by default constants.VI_TMO_IMMEDIATE.
- Returns
VISASession – Unique logical identifier reference to a session.
StatusCode – Return value of the library call.
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open_resource
(resource_name: str, access_mode: pyvisa.constants.AccessModes = <AccessModes.no_lock: 0>, open_timeout: int = 0, resource_pyclass: Optional[Type[Resource]] = None, **kwargs: Any) → Resource[source]¶ Return an instrument for the resource name.
- Parameters
resource_name (str) – Name or alias of the resource to open.
access_mode (constants.AccessModes, optional) – Specifies the mode by which the resource is to be accessed, by default constants.AccessModes.no_lock
open_timeout (int, optional) – If the
access_mode
parameter requests a lock, then this parameter specifies the absolute time period (in milliseconds) that the resource waits to get unlocked before this operation returns an error, by default constants.VI_TMO_IMMEDIATE.resource_pyclass (Optional[Type[Resource]], optional) – Resource Python class to use to instantiate the Resource. Defaults to None: select based on the resource name.
kwargs (Any) – Keyword arguments to be used to change instrument attributes after construction.
- Returns
Subclass of Resource matching the resource.
- Return type
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resource_info
(resource_name: str, extended: bool = True) → pyvisa.highlevel.ResourceInfo[source]¶ Get the (extended) information of a particular resource.
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property
session
¶ Resource Manager session handle.
- Raises
errors.InvalidSession – Raised if the session is closed.
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property