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
[source]¶ VISA Resource Manager.
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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.
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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) → 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.
Parameters:
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session
¶ Resource Manager session handle.
Raises: errors.InvalidSession
– Raised if the session is closed.
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