SCPI Class

class scpi.SCPI(cmd_list, comm_handle, name='not named', unconnected=False)

A SCPI (or SCPI like) instrument with a list of commands. The instrument has methods to get and set info of each command.

Parameters:

cmd_list : Command

A list of commands. Each command is an object of the class Command

comm_handle : Communication object

handle to the (general) hardware interface Example is the pyvisa instrument object: inst Needed when commands are overriden must have a:

write method (Examples are pySerial write() or pyvisa inst.write()) and an ask method (Examples are pySerial ask() and pyvisa inst.query())

name : str, optional

Name of the instrument

unconnected : bool, optional

For simulation & testing without instruments If true a “fake” ask and write command are configured. Ask always returns the same value (getter_debug_value).

Attributes:

unconnected : bool

if True the instrument is unconnected and returns appropriately configured garbage values just for testing

vendor_id : str

id returned by the identification command

name : str

name the user assigns

comm_handle : object

the communication object (could be from pyvisa or pyserial)

Methods

get(name, configs={}) :	get the value for the command of a given name
set(name, value=None, configs={}) :	set a value for the command of name
list_cmds() :	print all cmds
help_all(subsystem_list=None) :	list help for all commands (or for commands within a list of subsystems)
help(name):	print help on a command of the provided name
log_all_getters(filename=None, suppress_stdout=False):	write all values that can be read to a file or to stdout
test_command(name, set_vals=None, get_configs={}, set_configs={}):	test a specific command by sending a value and checking the readback of that value
test_all(skip_subsystem=[‘setup’, ‘status’, ‘system’],	skip_commands=[‘fast_transfer’, ‘reset’]) : test all commands

check_set_range(value, name)

check if the value to be set is within range

Parameters:

name : string

name of the command (first column in the csv file)

value : Union[str, int, float, None]

the value to set

Returns:

bool

True if in range

help(name)

print help for a single command

Parameters:

name : str

the name of the command

help_all(subsystem_list=None)

print help for all commands

Parameters:

subsystem_list : list, optional

a list of subsystems to limit the printing to

name : string

name of the command (first column in the csv file)

list_cmds()

list all commands

log_all_getters(filename=None, suppress_stdout=False)

save all gettable values to a file and send to stdout

Parameters:

filename : str, optional

name of the file (if None no file is saved)

suppress_stdout : bool, optional

if True the getters will not be printed to stdout

Returns:

dict

dictionary with the command name as keys and the results as values

out_of_range_warning(value, name)

throw a warning

Parameters:

value : Union[str, int, float, None]

the value to set

name : string

name of the command (first column in the csv file)

Returns:

UserWarning

read_comm_err()

Read if the instrument has flagged a communciation error

The csv command file must have a getter with name comm_error that returns a bool

Returns:

bool

if True a comm error was detected

set(name, value=None, configs={})

set a value

Parameters:

name : string

name of the command (first column in the csv file)

value : Union[str, int, float, None]

the value to set

configs : dict, optional

special configurations beyond the ‘value’; specified in the csv file

Returns:

str

Todo

check this and fix?

test_all(skip_subsystem=['setup', 'status', 'system'], skip_commands=['fast_transfer', 'reset'])

Test all commands by setting and getting to determine if: 1) the instrument reports a communcation error 2) the return value is of an unexpected type or an error threshold away from what was set

Parameters:

skip_subsystem : list (of strings), default = [‘setup’, ‘status’]

subsystems to skip, an example might be commands in the status subsystem that reset the instrument

skip_commands : list (of strings), default = [‘fast_transfer’, ‘reset’]

Commands to skip

Returns:

dict

Keys are each commands tested, value is True (command succeeded) or False (command errored)

test_command(name, set_vals=None, get_configs={}, set_configs={})

Test a command by setting and getting to determine if: 1) the instrument reports a communcation error 2) the return value is of an unexpected type or an error threshold away from what was set

Parameters:

name : str

Name of the command

set_vals : list, optional

A list of values to test by a sequence of set and get. If not provided the low and high limits are used

get_configs : dict, optional

A dictionary of configs to send the get command

set_configs : dict, optional

A dictionary of configs to send the set command

Returns:

bool

True if the command is successful, False otherwise.